I built a radiator cart, and just roll it up to the engine assembly stand. Attach hoses and cables, add fuel, and a chain from the cherry picker for added stability. Exhaust is from my old '67 Dart Slant 6, with some minor mods to connect to a V-8.
Radiator cart legs and gauge panel fold up for storage.
Photos of Pontiac 455 from a couple years ago.