Depends on if it's a Procharger, Magnuson or turbo. That's fine for a Magnuson but I would want more with a turbo. Like 10 to 1. My Procharger will break up a little in the upper RPM with the stock compression of the 6.1 but only in good air. I tuned most of it out with a plug change but the predator only gives you very little adjustment. This is with the 10PSI pully