I have a set of ported LS6 heads and a set of ported 6.0ltr 317 heads. I'm looking to raise the compression in my 03 Denali from the stock 9.5 to 10 or 10.5 max. I will end up doing a head and cam upgrade on my truck over the winter. I'm wondering if I should use the ported LS6 heads because of the smaller and more effecient combustion chambers or mill my 317 to yield my desired compression. What do you guys think my compression whould jump to from my stock 317's to the LS6's that have around 65cc's. Also how much do I need to mill off of my 317 heads to acheive 10 to 1 or 10.5 to 1. What is the highest compression that I should run with 93 octane. I am looking at a cam in the 224-228 range with around 560-580's lift w/ 114 so that I can also hit it with a little spray.

 

I know ls6 heads on the LQ9 bring it to around 11.1