the ls does have lower compression than the gsr. i was not saying it had a 10:1 ratio. i just used that ratio as an example. and btw, you can run a hella lot more boost than 10psi with a 10:1 ratio. all you need is a competent tuner. running lower compression just leaves more room for tuning error. anything below 9:1 is too low. period. if you look at most drag cars, they run decently high compression ratios. they can do that because they run strictly on race gas and can keep it from detonating. that low compression is better for boost is an internet myth. oh and i have a turbo gsr.