Tan 79, I just finished this same exact swap and it works great in my 84 GW. I ended up using a tank from a 1993 Chevy/GMC G20 Van (21 gallon). It had the factory drop in fuel pump which i swapped for a Walbro 255, i also relocated the factory jeep sending unit to fit in there. I used Novak's motor mounts and radiator. Factory LM7 Truck manifolds wouldnt work for me (interfered with trans shift linkage), instead i used factory 5th gen Camaro manifolds since they dump straight down and not on an angle.
For the NP241c i grabbed one out of a wrecking yard off a 1993 1500 Chevy (driver drop) used the SYE kit from JB Conversions and also used thier shifter. The front output on the NP241c had a weird flange that i wasn't sure i can adapt. So i swapped it to a 1310 CV style yoke, this required changing out the front output shaft to one from a Dodge's NP241 (light duty version) found on ebay. With the BJ's 6" lift 4.10 gears and 33" tires im getting 17 mpg on the highway.
P.S. the small threaded ports between the upper and lower radiator hose mounts aren't for trans cooler they are for steam port (LS requirment) or for a temp sensor. I learned the hard way and pumped a bunch of coolant into my trans.
Good luck with everything, feel free to PM me.