how much compression will decking the block 20 thousanths give me...... this is on a 350 being bored 60 over and i have 441 76cc open chamberd heads and im going to be running a KB 120 piston with 2 valve reliefs.....with the 76 cc heads it tells me 8.9........and i want to be able to run pump gas so...... will i be able to....

Being able to run pump gas is dependant on a lot of things, your static compression ratio being just one of them. I'm sure that you can get away with running pump gas through that engine. I'll bet you could get away with mid-grade or even regular depending on your altitude and combo setup.

south east okla and I have the comp Xtreme Energy 268H-10.......