chevyman1937--I'm pretty sure you're right. The most I'd run would be around 10-12 psi constantly, but I'd make sure the engine was built for it first. It's going to be a loooong time before I can get a turbo or a centrifugal supercharger. I can't decide which one to go with. Maybe one of each. Some day. Anyway, there's a guy at my school who has a Grand Natiol with the original motor and turbo. Pretty neat stuff. Now only if I can get him to donate it to me. Thanks again guys. John.

'68 C-10 - 250 with Edelbrock 600cfm 4 barrel, Offy intake, Hedman headers and true duals, HEI, MSD 6A box, relocated gas tank
Soon to have: T-5 tranny