I am going to be buying heads and was thinking of buying patriot 5.3l but i won't to know how much they will raise my compression over my stock 5.7 ls1 heads. I will be using gm head gaskets. I am looking for a good estimate.
also anyone know if the 7.4" pushrods would be the right set up to use with these heads an a thunder racing cheater cam. I really hope so i just bought them. Will these heads cause me to lose piston to valve clearance?

Thanks Dan

 

Compression
And...
Heads specs

and...
The chambers on the 5.3 heads are .030" lower thean the 5.7 heads.