Pontiac Heads......

[StealBlueZ]

.....on a BBC. What are the pro's & cons. I will be changing mine out this offseason and am curious about the Pontiacs. Will they fit a 502 and would it be better than Dart, Merlin Chevy or others?

[DogHouse]

That depends on what you're calling "Pontiacs"!
:wink:

[DEL51]

You really have to evaluate the engine application. The "Pontiac Heads" also called the big chief are pretty much a race only design, The intake ports are lined up different than a standard big block head.Head angle to the block, valve positions and other associated parts will not match a standard chev big block system.That said: They offer huge Valve sizes and efficient combustion chambers. This allows minimal piston dome height for less piston weight and better ignition and flame travel.In my opinion it would cost about 5 thousand bucks to have a complete pontiac system for the 502. This is usually used on Pro stock- high rpm engines in drag racing. Warren Johnson uses the same 500 inch displacemant as a 502 stock chev but it is a different animal.The 1100+ hp engines have a large cylinder bore, 4.6 inches or more, and a shorter stoke crank. These are high rpm.The heads have been used on a marine engine or two but the cost is about 30K.You end up with a 1100 horse engine that could be as good power wise, as a blown 540-572 for 15-17 thousand dollars. Weight is also a factor if you are planning on racing.

[Just Tool'n]

We use to have those heads on a Pro-Gas Flat bottom 11 years ago. They where nice heads, big ports, had 2 dominators on them, that were cut down the center.
I do not think I would use these heads on anything except a race motor.
I am sure there are better heads for a pleasure boat.
Talk to a good marine engine builder, Or go to the blower motor section, & ask Infomanic, he knows everthing.