throttle body to carburetor swap

What happened with the transmission is, i blew the original in my dodge ram d-100, i swapped that transmission with my 89 dodge ramchargers, this transmission was about 4 inches shorter then the previous, after the swap The transmission was slipping, it has around 180k miles on it, so im geared more to dropping this RV 440 and transmission into it. my RV has bout 40k miles on everything. Im pretty sure my current trany wont last long esspecially this truck being a farm work truck i haul hay with this truck, dirt post's anything on the farm, so im geared towards the big block idea. How hard would it be to drop the 440 in my truck? and bypass all the electronics?