[truckster]

While I agree that "all original" does sound cool, what does it really mean? If you're rebuilding the engine, then the only things that are likely to be original are the block, crank, maybe the heads and rods. What about things like tires, brake pads, glass, etc. My point is that vehicles don't stay all original if they're driven.

Build the truck you want. But as an alternative to the LS swap, you might consider the L31 Vortec. Your brackets and accessories should bolt in place, and you get a roller cam, the best-flowing heads GM put on a Gen I SBC, a rear main seal, and great reliability. The swap is going to be simpler than an LS swap - you'll need an intake (different bolt pattern), mellonized gear for your distributor, and most likely an electric fuel pump.

And you can always stick the original engine in a corner of the garage in case you decide you want to put it back in some day.