Chucknorris79

I have been looking to see which set of heads I'm going to buy for my lq4. I was looking at ls6 head (pn 88958665) and I understand this will work for my built with 10.5:1 compression. But there is another ls6 option with a larger combustion chamber( I think I said that right) and that's pn 88958622 with a 11.5:1 compression. My question is if I go with the head that has 11.5:1 compression do I have to change my pistons if they are in good shape? And/or do I have to bore and hone the the engine also?

ND2RACE

You'll find that most people refer to the heads by their casting numbers, LS6/LS2 heads use the same head casting with different valves (lightweight valves in the LS6), cast as a 243. Your LQ4 has the ever popular 317 head on it from the factory, the 317 is said to be the same as the LS2 head with bigger chambers.

The part numbers you posted there look to be discontined so I'm not sure what good those are going to for you anyway.

Everything you've talked about will bolt right onto your LQ4 with no need to do anything to your pistons or short block in general. The only thing that would cause issue is running some wild camshaft that may effect clearance inside the engine but I seriously doubt you'd be doing something radical.

The heads on the engine already could be ported for flow and decked to raise compression giving you a decent budget option. Hope this helps.