8.5 or 9:1 compression pistons

I'd go with the 8.5's if you're going to be blown. I doubt drivability or fuel economy would change much, but when the pressures on or the temperature starts to climb, you're a lot less likely to experience detonation as appose to the higher compression slugs. Besides, you’ll get away with pulling less timing and being able to run higher boost pressure with the lesser compression pistons, which is why it’s recommended….besides, 8-10psi isn’t all that little boost on a multipurpose engine anyway, so the safer the better.