late model serpentine swap
Well if it was to happen and you have a spare belt you just turn the AC off and put the new belt on. With the AC off the compressor is not longer linked to the pulley the belt is riding on and at that point it's just an idler.
Anyway, back to the original question. YOU MUST use the magnum front cover and water pump along with the magnum fan clutch (threads onto the water pump verse being held by 4 bolts) and fan. The serpentine system on the late models turn the water pump and fan in the opposite direction than on an LA.
If you want to do this I would measure from the front of the block to the front edge of the fan on a magnum motor and make sure you have clearance for everything.