Yeah man, for a short bed I think a single shaft is prob the way to go unless you have clearance problems just because it's easier to measure and deal with. But really if you keep the 2 piece I don't see why that would be a problem even with the 4l80. You just need to shorten the front piece and make sure they supply the correct end to support your 4l80 size u-joints. But if you're planning power, you will at the very least need to upgrade that carrier bearing. Then research the 12 bolt Chevy rear and how to beef it up at the pinion. Then the driveshaft diameter is next weakest link. I think that's right order.
Sanding down those blocks should work, but I just bought some on Amazon for pretty cheap so it's cash vs time on that idea IMO.
