[PAUL K]

Nothing has changed. It takes a lot of work to make the longer strokes make competitive power in a traditional Pontiac engine. Seldom would I use a 4.5 arm in a factory block build. Very narrow spectrum that one will shine when used in a stock block. Just because folks build them, it doesn't mean they make good power.

[Jay S]

I used a .140” thick Cometic head gasket with a 4.5 stroker to use a longer rod in a short deck platform with a 4.5” crank and 6.7” rods. The pistons were above the deck .1” or more. With the right piston it would be close using a 7” rod and 4.5” crank in a Pontiac doing something similar. 6.86” ish for the 4.75”. I took the Cometics apart and stacked them to get the height I wanted. The height I end up with was available from Cometic. I suppose you could stack the Cometic's and go taller yet. I was running out of room on the top rings, there was a little more room though. lol

[mysticmissle]

Originally Posted by Jay S

I used a .140” thick Cometic head gasket with a 4.5 stroker to use a longer rod in a short deck platform with a 4.5” crank and 6.7” rods. The pistons were above the deck .1” or more. With the right piston it would be close using a 7” rod and 4.5” crank in a Pontiac doing something similar. 6.86” ish for the 4.75”. I took the Cometics apart and stacked them to get the height I wanted. The height I end up with was available from Cometic. I suppose you could stack the Cometic's and go taller yet. I was running out of room on the top rings, there was a little more room though. lol

no issues with all those layers? did you spray each layer?

[Jay S]

Originally Posted by mysticmissle

no issues with all those layers? did you spray each layer?

I didn’t spray that one. I could see where that might be necessary though.

That particular engine used Evans waterless coolant, which seems like it is more forgiving to seal up than antifreeze, there is more or less no radiator pressure with that coolant.