[lowrollin70gmc]

Swap everything to the 72. Motor should bolt in with 72 motor mounts (Small block to small block, big block to big block). Trans should fit moving the crossmember and drilling new holes. Then remove fuel injection wiring and transfer over to 72 or get stand alone wiring/conversion. Brake booster (if hydroboost) should transfer over with some bracket fab or an Astro Van mounting plate.

I wouldn't take on all the fabrication required to put a 72 cab on a 94 floor. Cab swap would be okay but overall the best way is to transfer drivetrain and play with the wiring side of it. Quite a few people have done TBI swaps and you should be able to find them on this site / google for more info than you can shake a stick at. Fabbing small brackets and wiring changes are much simpler and more likely to be finished than splitting a cab in half.