I have a 5.3L and got myself into a little bind. i need to replace my heads and all i can get my hands on right now is a set of LS1 heads. I'm having them milled to try to retain stock compression due to the bigger cc's on the LS1 heads. My question is head gaskets. 5.3L head gaskets are made for aluminum to cast iron. LS1 head gasket are made for Aluminum (heads) to Aluminum (Block). i wanted to use LS1 head gaskets and bolts but ......after thinking about it, are LS1 gaskets the same material as 5.3L head gaskets. I know guys do 5.3L head swaps on to LS1 to raise compression, I'm just doing the opposite. what gasket do you think i should use, gasket to match head or gasket to match engine block????? Thanks

 

You need to use a 5.7l head gasket. It's a bad thing when the cylinder bore or the chamber is larger than the head gasket bore.

Good luck,

Richard