| Author |
Message |
    
powassan
New member
Username: powassan
Post Number: 1
Registered: 12-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, December 23, 2005 - 12:04 am: |       |
I have in my car, a 350 Chev v-8 from a 1989 GMC Sierra. Its a throttle body injection. I acquired a set of Vortec heads from a 1998 GMC 350. I am putting these heads onto my TBI engine to make a Vortec TBI 350.
Also in this 1998 engine was a set of roller lifters, pushrods, and the spider to hold the alignment plates in for the lifters. There is a manifold avaliable that adapts a throttle body to vortec heads. GM is the only one that offers it and they want like $1000.00 for this manifold. I called our Edelbrock Parts Supplier and ordered a #2116 Vortec manifold. Its for a 4 BBL carb. There is plates avaliable that bolt to a 4 BBL manifold, but has three more bolt holes for a throttle body instead. I am going to make one from aluminum and use it. I want to keep it TBI for the rest of the winter, as the cold starting is sooo easy with TBI vs a 4 BBL.
My question is this: Will the roller lifters, spider, and pushrods simply drop into the 1989 block? Also the heads on the TBI now have something like 76 CC chambers, whereas the Vortec heads have 64 CC chambers. Any idea on what my compression is gonna go up to?
Also, in regards to camshafts, if I use the camshaft out of the 1998 GMC Vortec Engine, will I need to change the distributor gear, or should I not bother using it because the vaccume differences will screw with the TBI computer?
-Thanks.
|
pontiacivan
New member
Username: pontiacivan
Post Number: 10
Registered: 11-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, December 23, 2005 - 11:50 pm: | |
I am currently performing this exact swap. Compression with the Vortec heads and stock head gasket will come out to around 10.5:1. If you use the GM head gasket 12557236 you will lower compression to 9.5:1. The lifters,spider and pushrods are all bolt on for your block.Make sure you get the cam retainer plate. If you can get the distributor from the Vortec engine I would suggest you do so. If you can't I beleive you can purchase a melonized gear from GM that will work better than a bronze gear.You should also be able to run any small cap distributor from a factory roller cammed TPI V8 engine. Vaccum should not be a problem since the Vortec cam is designed for computer use and is actually shorter at .050 than the TBI. There are some disagreements on this issue but this link should back me up http://www.megspace.com/cars/16147060/Eng_Cam.html (Apologies to Sallee if this is a competitor site) The 350 police TBI uses an even longer cam at .050. The big issue is the lobe seperation angle. On all the stock EFI GM cams it is wide enough to promote compatible vaccuum. You may also hear that the flow increase of the Vortec heads will cause problems with the ECM. I have not been able to find any hard confirmation for this. The Vortec heads have flow similar to non- swirl heads on the intake side (AT THE LIFT WE ARE TALKING ABOUT). Where they have dramatically increased flow is on the exhaust side. Basically you are getting a head that flows like a stock head using a cat forward header exhaust but Does it using exhaust manifolds. I would also like to suggest the Holley TBI adapter 517-1 since it has a hollow cavity and ports for coolant. If you skip this you may find your cold start will be less than desirable. I would like to continue to swap ideas and experiences with you on this project since we are doing the same thing. |
57hardtop
Junior Member
Username: 57hardtop
Post Number: 18
Registered: 10-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, December 23, 2005 - 11:56 pm: | |
"There is a manifold avaliable that adapts a throttle body to vortec heads. GM is the only one that offers it and they want like $1000.00 "
in regards to this remark i believe you are inquiring about the same intake offer by summit racing that is only $309.00. here is the part number # NAL-12496821. sorry not to have all your answers. hopefully admin will help |
powassan
New member
Username: powassan
Post Number: 2
Registered: 12-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, December 24, 2005 - 3:53 pm: | |
Awesome, I started Friday night, and right now I am cleaning up the block to put the heads back on. The only problem I have encountered so far is that the cam from the Vortec engine needs a retainer plate. The bolt pattern on my 89 block is wider than the bolt pattern for the plate on the Vortec. Where can I get a retainer plate that will bolt to my block and suit the cam?
As for the manifold, I ordered one from Edelbrock already for $289. P/N 2116. Also, the gear on my distributor appears to be iron, I put a magnet on it and it stuck pretty well, so its not bronze.
-Will keep updating. Thanks. Nick. |
scott
Senior Member
Username: scott
Post Number: 470
Registered: 4-2001
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, December 25, 2005 - 2:01 am: | |
On your 2116, where are you going to install your EGR valve? Sallee Chevrolet sells the 2116 Edelbrock manifold for $151. I would cancel the $289 order if possible. The system requires an EGR valve to work, and you are in for a world of problems with this swap. The GM intake #12496821 would work for what you are doing, and Sallee sells this intake as well. You need a new distributor gear on your TBI engine's distributor. Any time you install a different camshaft (especially a roller camshaft), you need a new factory GM distributor for your application. I wish you good luck with your project. |
pontiacivan
Junior Member
Username: pontiacivan
Post Number: 11
Registered: 11-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, December 26, 2005 - 11:31 am: | |
Quote:"you are in for a world of problems with this swap" I'm not sure what this statement is suppossed to mean.Please do not tell people that customizing their vehicles is too difficult. DIYers are in this for the experience as well as the gains.If you had ever performed the Vortec head swap your quote would read " This swap involved some careful planning and thought, but was worth it." This is a pretty straight forward swap.There is nothing involved that a manifold swap on a carb engine might not have called for in the old days.We were making brackets and adapters and custom fuel lines years ago.And if there was a Holley carb involved then there was even more to make. The toughest part is the EGR issue and I will tell you how I handled it shortly. First the cam/distributor issue.A new distibutor for a cam install? GM doesn't even do this on warranty repairs.No magazine article or shop manual has ever mentioned such a need. Make sure your distributor is in good functional shape and you are OK. Find a salvage yard that has Camaros,Firebirds or Caprices with TBI. Ask them for a retainer plate and distributor from a core engine. End of problem. The distibutor gear is correct for your roller cam and the cam plate will fit your block.I am using the Edelbrock intake. Here is how you I handled the
EGR issue. Find a block of aluminum large enough for your EGR valve to sit on and fabricate a mount for it to attatch to the engine.You can mount it on the exhaust manifold, the intake or any place you can get exhaust gas to it using a steel line without getting close to fuel lines or flammable items like plstice MAP sensors and such. Using and old gasket drill the block for the two mounting bolts and tap them. Drill a hole for the exhaust to enter the valve in the proper location and drill and tap for an NPT to brake line fitting. Use largest diameter of steel brake line you can get. Run the other end to the Vortec exhaust manifold and use adapters if needed to connect it the EGR gas port. I have headers which have an oxygen sensor port on each side so I used the extra port on the passenger side header. Drill and tap a hole for the intake side of the EGR valve and screw an appropriate fitting into this hole. I used an NPT to female brake line. Drill a matching hole in your TBI adapter and install the same fitting. Connect them with the correct size steel line and make sure all your lines are away from fuel, wiring etc. you can drill straight through the block for simplicity or you can drill down from the top and in from the side for a 90 degree setup.It all depends on how tricky you want to be. Remeber that aluminum will snap a tap designed for steel with out much effort. Use an aluminum tap or go real slow and use lots of lube. Use common sense here, you are working on an engine using non stock parts and fabricating solutions. If you have a visual emissions inspetion, remember that the neater your installation, the less likely you are to be hassled. In NY the valve only needs to be present and connected. If you get an inspector that wants to interpret the law, get his manager involved or find another shop.There responsibility is to determine compliance based on the criteria for inspection, not whether or not they like your solution.Let me know if you need a better description or have any other questions about this swap. I just found a Police TBI with the 65LB injectors and the ECM. I'm looking into what I need to use this ECM since it is not the same as the one in our trucks. |
scott
Senior Member
Username: scott
Post Number: 471
Registered: 4-2001
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, December 26, 2005 - 4:00 pm: | |
Quote: ".A new distibutor for a cam install?". I apologize for leaving out the word GEAR in my post, I should have proof-read more carefully. I only recommend changing the GEAR, not the whole distributor. GM isn't going to recommend changing anything on warranty that they don't absolutely have to. Do you want to jeopardize your whole swap and engine because of a $25 gear or a junk yard distributor? As for your EGR adapter, if you can make it work, more power to you. GM does have a TBI intake for much, much less than $1,000, and it would have bolted on and worked with absolutely no problem at all. You are correct in assuming that I have never done a Vortec head swap on to a TBI engine. I have however, tried to help DOZENS of people with problems with Vortec swaps. I must admit to not being a fan of this conversion, as it costs me considerable amounts of time answering questions both here on the message board, as well as on the tech line. I may have under-estimated your abilities, and if so, I apologize and wish you well with your project. }
(Message edited by scott on December 26, 2005)
(Message edited by scott on December 26, 2005) |
pontiacivan
Junior Member
Username: pontiacivan
Post Number: 12
Registered: 11-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 27, 2005 - 5:17 pm: | |
OK, My apologies, I am glad you cleared that up as it was quite shocking to read. I'm sorry to hear you are not fond of this head swap. It really is the best thing anyone can do for their small block Chevy if they are not race only. Everything seems to be better with these heads; power,economy, emissions, preignition resitance. In my honest opinion, the only real problem with this swap is the price tag on the GM intake that has the EGR solution built in. When a new part is introduced on the market, it's price is dictated by demand, research and development and production cost.This part had all the hard work done for it long ago. It should have been very simple for GM to tool up and produce these for around $150 and still sit pretty profit wise. Edelbrock should bear some responsibility here as well. Why haven't they come out with an EGR version yet? Oh, wait...they do. The multipoint manifold for Vortec heads has EGR. Again, this is a case of the manufacturer pricing an item WAY above the R&D/manufacturing costs. The multipoint system is cool, but is essentially 15 year old technology. It uses a TBI ECM with what basically amounts to modified TPI injectors on a very simplistic single plain dry flow manifold and tweaked chip programming. But I am now way of subject. Again my apologies. I joined the forum to exchange ideas and sometimes get a little excited. |
powassan
New member
Username: powassan
Post Number: 3
Registered: 12-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 27, 2005 - 5:20 pm: | |
I ordered a single roller timing gear and chain set from GM. The set comes with both types of retainers, including the one I need for this block. I have the heads bolted down, and I also ordered a set of headers. I will put the manifold on tomorrow, and wait for the gear set, which will be in Thursday. This was a pretty simple swap, just takes lots of time, and a little bit of $$. For the gains, I think it will be worth it. |
powassan
New member
Username: powassan
Post Number: 4
Registered: 12-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, December 29, 2005 - 9:56 am: | |
Also watch when using an edelbrock intake. The Fel-Pro hard plastic gaskets that are used stock will not fit the intake. Now I gotta wait another day for gaskets :S |
pontiacivan
Junior Member
Username: pontiacivan
Post Number: 13
Registered: 11-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, December 29, 2005 - 5:07 pm: | |
Someone told me abouthe gasket thing, maybe even Edelbrock. I got the suggested gaskets up front. Did you get GM intake bolts with the ball shaped shank or are you using hardware store bolts? |
powassan
New member
Username: powassan
Post Number: 5
Registered: 12-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, January 1, 2006 - 5:45 pm: | |
I used the GM bolts for the heads and manifold. And yes, I used edelbrock intake gaskets, I had to.
Well, I got it all back together and it runs like an absolute pile of crap.  When its cold for the first two minutes itll run like a clock. Then it warms up and runs horridly. I give it gas and it just chugs and sputters along. I hope all it is, is a timing advance that I need to do. Im going to run premium fuel in it from now on, as the compression undoubtedly went up.
Another problem I am now encountering is the oil pressure. I drive it for 15 minutes or so and get it all warmed up and if I let it fall below 1500 RPMs my oil pressure just drops. I will have to look into it more, and I drove it last night, noticed the oil pressure issue so I let it sit overnight. Before I went off to bed after driving it I checked the oil level and it was very low. After that I checked this morning and the oil level was back up. 
Mmm, Im scared now that I might not have done something right. I will check timing again and if thats not it, I might just bolt a 4 BBL on. Because I did the carb to TBI conversion in an 83 Pontiac, there is no vehicle speed sensor for the computer to know how fast im going, thus it may not control the injectors properly.
(Message edited by powassan on January 1, 2006) |
powassan
New member
Username: powassan
Post Number: 6
Registered: 12-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 2, 2006 - 9:21 pm: | |
Well its all together, the timing is dead on, the fuel pressure is more than adequate with the adjustable pressure regulator and high pressure pump I put on, and it still runs like a ford. From an idle in drive it just dies right down and sometimes stalls. I dont know if I need a new distributor or what, but it sure aint workin like it should. I had the timing marks lined up on the cam and crank, the balancer and timing cover are the same as before. Im running out of ideas. I think I might just ditch the TBI in favour of an old carb and distributor. |
pontiacivan
Junior Member
Username: pontiacivan
Post Number: 15
Registered: 11-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 2, 2006 - 10:54 pm: | |
Did you ever have the stock TBI running in this car before the head upgrade? Also where is this high pressure pump installed? Did you install a fuel tank with the pump from a TBI car? I agree that something is wrong but don't abandon the TBI until you sort out the other problems first. The oil pressure problem concerns me most since nothing involved in a head swap should affect this.I just finished my swap and throttle response is crisp and acceleration is noticably better .than the old heads. Let me know |
powassan
New member
Username: powassan
Post Number: 7
Registered: 12-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 2, 2006 - 11:55 pm: | |
Yes, I have had the TBI going for about a year now. It always did have somewhat of a hesitation, I used to run it in the summer with the temp sensor unplugged and plugged into another sitting on the manifold to richen it up. The pump is installed in front of the fuel tank, above it. The tank is from a late 80's Monte Carlo or Cutlass I think, it has the provisions for the in tank pump.
Checked everything again, timing, manifold vaccume, fuel flow and pressure, and timing. I decided to pull the distributor and I found two cracks in the magnet. Im gonna order another distributor tomorrow, this was fooling the computer into sending a spark out for 10 cylinders instead of 8.
As for the oil pressure, its concerning me too. I dont know if I have a faulty sensor or what. It always dropped down before, but now at an idle after it gets hot it drops pretty far past 0. I had to sit there and rev it to 1500 for the pressure to come up. It shoulden't need a new oil pump yet... The block was a new shortblock from GM out of a truck. The guy gave it to us after the rest of the truck was shot and the new block only had about 50,000 on it.
(Message edited by powassan on January 3, 2006) |
powassan
New member
Username: powassan
Post Number: 8
Registered: 12-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, January 4, 2006 - 10:08 pm: | |
Checked fuel pressure under load and it was pretty restrictive. I am now replacing the lines and filter. Hopefully this clears things up. Also, the high pressure pump is mounted below the tank not above like I said before. |
scott
Senior Member
Username: scott
Post Number: 473
Registered: 4-2001
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 5, 2006 - 1:38 am: | |
Not to be negative or anything, but these are the typical problems that crop up with Vortec head swaps into TBI applications. What computer are you using? What did the donor TBI system come from? From the sounds of things, you need some re-calibration to make this work. Is your EGR functional? There are custom chip manufacurers out there that can probably help you make your engine run. The Vortec heads flow considerably more air than the swirl port heads you removed from the engine, and will therefore need more fuel. |
pontiacivan
Junior Member
Username: pontiacivan
Post Number: 16
Registered: 11-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 5, 2006 - 9:24 pm: | |
Powassan: Your problems are because you started with an engine that was not running correctly first, not because the Vortec heads flow too much for your TBI. Shame on you, consider yourself chastised  . If you altered your compression by using the wrong head gasket, please change to the part number I suggested. You can make this work, but you've got to get your original problem sorted out.
Scott: At the risk of starting an online rivalry, something I do not wish to do, you have incorrectly formed an opinion of these heads that they do not deserve. Please, (PLEASE) no matter what your history or background in the automotive industry is, spend some time online searching these relevant facts. The Vortec heads do not flow significantly more air than the swirl ports in the .300 to .450 lift area on the intake side. They flow about the same as most Chevy heads. They flow better on the EXHAUST side, where most Chevy heads fall down. Also Exhaust airflow has less impact on a computer controled vehicle as proven by the healthy cat- forward/cat-back exhaust business. The Vortec heads generally require less fuel to make the same power due to their advanced combustion chamber, this is why the swirl port head was discontinued and the Vortec was created. Swirl is late 80s early 90s.Combined swirl, tumble and agitation is where technology has evolved.
The EGR valve is required for emissions compliance and I would never suggest removal, but is not an essential part of the ECM's programming. As long as the solenoid is connected so a code is not set and no vacuum lines are run to it, the ECM won't care if the valve works or not. Re-calibration can help make more power once Powassan's engine is corectly running, but shouldn't be needed to make this swap work if compression is left stock since the cam used will make excellent vaccum for the ECM to calculate fuel mixture from.All of these facts are well documneted. Now that I have finished my swap ( My TBI engine was in very good running condition before I started.) I am going to start calculating fuel mileage to see what increases i might have gained. I would estimate power at around 260HP and torque around 350Lbs/ft. I can cruise in overdrive without constantly downshifting due to poor low end torque. This was one of the most satisfying upgrades I have done in recent years. It was also one of the easiest, no surprise jobs I have EVER done. I'm sorry, but I'm going to defend the Vortec head swap as THE Small Block Chevy upgrade to make carb or TBI. |
powassan
New member
Username: powassan
Post Number: 9
Registered: 12-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 6, 2006 - 6:54 pm: | |
I think the problem might lay in the fact that I have no VSS. Without the sensor the computer is not being told how fast I am going. I dont know if the TPS will compensate for this and add enough fuel to the engine or not. It is definitly running lean. It backfires through the intake. To make it driveable I put the fuel pressure to 15 PSI, and I unplugged the temp sensor and plugged it into one outside of the manifold sitting in the cooler air. This seems to richen it up substantially and it runs excellent. Im going to run on this until the spring rolls around, then switch to a 700 CFM carb. |
scott
Senior Member
Username: scott
Post Number: 474
Registered: 4-2001
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 7, 2006 - 11:36 pm: | |
Pontiacvan, there is absolutely no way that I will ever be able to convince you of anything, and therefore will just give up. Please accept my un-conditional surrender to your obviously superior knowledge. It's because of posts like yours, and the flood of tech questions that I get at work, that I rarely answer message board questions anymore.
I think it's time to take a LONG vacation from the message board. I'm tired of the hassles.....
|
pontiacivan
Junior Member
Username: pontiacivan
Post Number: 17
Registered: 11-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 9, 2006 - 4:58 pm: | |
Sigh!
Powassan: I'm sorry to hear you are going to give up the TBI for a carb. I hope your engine runs properly when you are done.
Scott: I'm shocked to read your response to my post. I will try to state my case one more time and then I too shall abandon this forum.
From the start I have tried to have a discussion on this subject with you. I have attempted to be polite and have apologized when I was wrong. I will not be as polite today. People who know me would describe me as humble and in no way a "know it all" ( my interpritation of your view of me.) I have a 100 mile long fuse and your post burned 99.99 miles of that in less than 100 words. You ARE correct that you will never be able to convince me of anything because you have failed on all ocassions to provide ANY facts on your position. By failing to offer any details as to why this swap has caused you so much anguish, then yes, my knowledge does appear to be superior to yours on this subject.To offend me enough to make me say such a conceited thing is wrong. In my last post I BEGGED you to look into my statements, but you only respond with insult. "The Great Tech Line Scott" has spoken and no details are needed? C'mon! I'm not sure what this "tech line" you are reffering to, but did it ever occur to you that tech support is FOR PEOLPE HAVING PROBLEMS? That's why I joined the forum, to discuss with people success as well as problems.No one calls tech lines to say how well there project is going.How about some sales numbers? How many pairs of these heads have been sold vs. how many people you have heard from with problems? I agree you should take a vacation from this forum and possibly from the "tech line" as well. You have a negative attitude and refuse to offer any supporting information for your opinion. Tired of the hassles? This is a text based message board where people discuss their experiences with parts combinations. So what if you and I disagree on this subject? Just state your facts and people will either agree or disagree with you. Leave the ego at the water cooler. That's it, I have no more to say. the admin can refuse to post this if desired. But either way I'm done with this board too. I just wanted to help Powassan get on track since we have the same swap going on and I am not having any of the troubles he's been having. |
admin
Board Administrator
Username: admin
Post Number: 2764
Registered: 8-2003
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 9, 2006 - 7:34 pm: | |
pontiacivan,
What I think Scott was trying to get at is that it's post like yours that give him all the headaches on the tech line. People tying to make projects like this work, that only the luckiest of people seem to be happy with the results and then try to convince everyone else this is the way to go.
As far as support for your side of the argument goes, you are as lacking in this as Scott was on his side. You saying do it, while Scott is saying don’t do it. The only thing that you have really stated as a fact that you can back up is that you did it and are happy with the results.
Your flow information on the Vortec heads is wrong for one:
“The Vortec heads do not flow significantly more air than the swirl ports in the .300 to .450 lift area on the intake side. They flow about the same as most Chevy heads. They flow better on the EXHAUST side, where most Chevy heads fall down.”
As soon as Scott can dig up that information for me, I'll put it on our Web site. I’ve been meaning to get that and put it on our site for a long time now anyway.
It's just aggravating for Scott to tell people to please not do something or you will be asking for problems like this poor chap powassan is going through, only to have someone like you come along and tell them to ignore Scott and encourage them to put more time and money down and bottomless hole. Ok, facts-to-fact is the way you want it. While I get the facts together on the Vortec heads, you get your facts together on them to back up your claims.
Little comments like this:
"The EGR valve is required for emissions compliance and I would never suggest removal, but is not an essential part of the ECM's programming. As long as the solenoid is connected so a code is not set and no vacuum lines are run to it, the ECM won't care if the valve works or not."
So why even bring up this subject if you would never and should never suggest this?
This set up less EGR valve, will cause detonation, and doesn't help your case much either. It's only going to make this poor guy’s problems even worse if he does it. We are trying to help people avoid problems not lead them into even more problems. |
bogie
Advanced Member
Username: bogie
Post Number: 190
Registered: 8-2003
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, January 10, 2006 - 3:48 pm: | |
jeeze, you guys made my eyes tired.
Getting a set of Vortecs onto a TBI block is no biggie, you just shouldn't have the problems you all are experiencing. First off the proper intake to adapt TBI to Vortec heads is widely available from a number of sources. For an intake you're looking for GMPP 12496821 TBI to Vortec head. Edlebrock used to sell one as well but it's no longer listed. To use EGR with the GMPP intake requires either the left side GM Vortec exhaust manifold 12557828 or a set of Edlebrock Vortec engine headers 66152 or 66153 which have the left side EGR source. You will need the GMPP EGR supply tube 10220275 or if you can still get it the Edlebrock 2899 EGR adapter kit. All this stuff will set you back 5-6 hundered bucks.
Old blocks being those from 1987 to 1995 may or may not have provisions for the factory roller cam. If the block came from a passenger car it probably does if it came from a truck provisions for a roller cam will run from none, to unmachined bosses, to everything you need maybe even including a roller cam and lifters. If you have a provisioned block all you have to do is drill and tap if this isn't already done. If you have an unprovisioned block, you just can't use the factory roller lifters and will have to provide a thrust button for the cam. A factory roller cam can be used in these type blocks with a factory style roller cam timing gear and chain set and a spacer to fill the distance over the cam snout between the back side of the cam gear and the block. This can be the factory retainer "thrust plate" and just drill and tap the block to hold it in place. You cannot use factory roller lifters in an unprovisioned block as they requre the lifter bores be about a half inch taller. Also the factory roller set up uses a shorter push rod.
You will need a custom chip and perhaps larger injectors depending on how many cubes and how much cam and compression you added, but for sure a custom chip with the heads if noting else was done. Otherwise the change in ai | |
New Post On GM Performance Parts And Aftermarket Performance Parts 
