Been there, done that, got the tee shirt.
The rig in my avitar was a 6.2L that I later swapped out for a 454cid. Easiest swap ever. 3 line fuel pump, ignition power to the coil, and homemade radiator hoses. Throttle cable, just a simple part swap. The torque converter on the 6.2 has different perimeters, but still works.
The 6.2 has a vacuum pump to operate the trans and hvac, so simple to plumb that hose in the manifold on the 454.