Hello Everyone,
I'm considering purchasing some stock 6.0L LQ9's cast #317 for my stock LS1.
I've read that the larger combustion cambers will lower my compression ratio, and i will need to get them milled to return my compression back to stock. How much will need to be milled?

What will I need to do to make these higher flowing heads work on my 5.7? Will a loss in my compression offset any gain in hp? How much hp would I expect to see?

I've also read about the valves being shrouded, what does that mean?

Will I need a new cover, or will the cover from my current stock heads work?

What about gaskets and bolts?

Will the stock internals on the heads hold up? I'm not running any power adders, but I may be doing a cam set up in the future and will upgrade springs ect accordingly.

Port and polishing a good idea?

Thanks in advance!
Haans

 

Any thoughts?

 

if your not doing forced induction or bigger motor you don't need the lq9's you need the ls6 heads. as far as the questions call up patriot performance and they will answer all of them. I suggest doing some more research before buying. Since your in michigan you not to far from epp in fort wayne, they sell everything you need and can answer all of your questions. good luck

 

Shrouding the valves means that the combustion chamber on an LS1 (3.898) is smaller than the chamber on the LQ9 heads (4.000), therefore the valves will be shrouded by the smaller chamber on the engine. As for upgrading to those heads, there is no reason to. The LS6 will help you more.