I am pretty sure that the output shaft is shorter on the 4WD tranny.

I have seen the shaft on a 2wd cut down to fit, but it has a limeted amount of splines engauged.

Make sure they both have the mount for a hydralic clutch. Some pickups used a cable clutch.

Early five speeds in the pickups used very difernat gears.

Other than that most parts should swap. Preferance should be given to use synrchros from the newer trans since they were often upgraded.

Kevin

87 Turbo Intercooled Raider, roller cam, torsen rear diff, LSD front diff, lockup auto with modified converter, V6 brakes, low transfer case gears...