Just my opinion, but 305s aren't the world's greatest motor by a long shot. They're not the worst, either. But they're sure not suited for making a lotta power. Small bore, limited combustion chamber and valve size, etc., etc.

If you've got a big ol truck that you want to move around, I'd think a big block (454 is probably the most common) would be the best way to go. It has just what you need: torque.

But what do I know? I'm just the bass player. smile

Ray
Enter the Chevy Asylum
"The Ugly Truck"