Man i am having trouble finding someone that knows anything local about a zz4 i need to know which one to get summit sells 10 different kinds the first brand being Percy's 1 called small chevy round 2nd. small chevy square.Earl's sells 6 different kinds for SB Chevy or i can get Flotech brand dead soft alum.at my local speed shop since my alum. heads have a D shaped exhaust port will these square shaped Flotech work?I have another problem i have Dynomax 1 5/8 that i want to use on these heads so i want a gasket that will last and not leak.Please help!!!

 

I use Felpro blue gaskets on my ZZ4 - they work great.

btw, GM reccomends 1 3/4" primary headers.

 

Whether it's a ZZ4 or not is really irrelevant. What is important is that you get headers that fit the exhaust ports. The primary flange hole has to be large enough to fit over the entire exhaust port. Then you match the gasket to the headers. I believe with "D" ports, round header primaries are recommended.