[elhigh]

Knoxville at 50, hey? Sounds like you're spending most of your time on Middlebrook Pike.

Don't be too creeped out, I work in Knoxville.

I know you like the older engines and I totally get that, and for my money I would say stick with the 305 you already have on hand. The volume/surface area ratio in that engine isn't too bad, so you don't lose quite as much heat through the cylinder walls. And the depth of support for the SBC is huge, so someone, somewhere has already done whatever you're going to do and you have a shot at picking that guy's brain for advice if you need it.

Having said that, consider an LLV, the big 2.9l four-banger the General screwed into the Colorado/Canyon twins. That's a bigger truck than your S10, but the engine's power output is right in line with what you're shooting for. You'll save about 150 lbs over just about any SBC, nearly the weight of an entire passenger. You'd have to swap over the EFI system but that just opens up all the EFI tuning options to you, and in that regard I just have to echo what everyone else has said: you're better off injected if you want the best possible economy.