0verkill

What's the highest compression you can get away with on a stock LS3? Using 93 octane, at sea level.

newschool72

iTrader: (12)

A stock LS3 has 10.7. Are you talking about shaving the heads? As far as LS engines in general, Ive heard of guys getting away with close to 12 to 1 WITH a spot on tune.

gnx7

iTrader: (28)

bigger cams allow for more compression also.....

You can run 11.25-11.5:1 on 91 octane.... so I would say close to 12:1 as well with 93.

litle88

iTrader: (20)

I'm stroke at 12.2 but I have a big cam to bleed it off a Lil on 93 octane.

WKMCD

iTrader: (2)

It's a balancing act with the LS3 heads. Too much CR and you can't crank in enough timing to make power. I ran 12:1 and could only run 24-25 degrees of lead. At 11:4, I ran 29 degrees and made more power. These heads LOVE timing.