[beaterku]

I have an LQ4 with 317 heads. I used stock GM LS3 head gaskets, milled the heads .030, had them CNC ported and running a smallish cam, it made around 475 at the crank. Stock bottom end with dished pistons.

I was originally going to swap out the flat top LQ9 pistons, but was sending the heads off to be ported anyway, so opted to have them milled. Put the comp ratio closer to 10:1. The engine runs great. To be honest, you are splitting hairs swapping heads. A lot of people poopoo 317 heads, but they are just fine.