The only thing that should remain from your 2v drivetrain when moving to a stout 4v is the block, the driveshaft, and the 8.8 rear differential.
EVERYTHING else goes away, and that really should include the transmission, clutch, and everything to do with the engine, fuel system and engine control system.
And yes, this is all quite possible to do, but extremely expensive (if done right) or extremely labor-intensive and PRETTY expensive (if done shade-tree-frankenstein from a variety of junkyard sources).
Wisest choice is to pick your horsepower goals and then seek advice as to how to achieve those goals (and what sort of driving you are going to do to USE those goals).
"You can never be free until you let yourself go."