Posted by Dave G. on December 01, 1998 at 15:58:21:
Hi,
maybe you can answer a question that I have been struggling with for a few weeks.
I have a 1997 Mercruiser (standard, not Mag)7.4 L that per the serial number is a Gen VI block. Does this
automatically mean that it has the Vortec heads or is it a GEN VI block with the small
port heads? Can I tell by looking at them (without removing the intake)? The intake is
my next question. I had a HiRel (now Holley)MPI system installed on it recently.
Hirel offered oval or rectangular port intakes. Would you think that the oval port intake
would be the larger ovals and not the small ovals. If I have the small port heads I will
want to change to the larger ovals such as Merlin or anything else "you" may suggest while
keeping the costly intake set up in tact. I've been told to stay away from the rectangulars because
in marine use you are trying to create the most power and torque while remaining under
5000 rpm making the large ovals a much better choice than the high rpm rectangulars.
If any of this makes sense, I would appreciate any input.
Thanks,
Dave G.