Except for the front driveshaft drop on different sides, is there a difference between the internal parts? I have an 89 Burb, NP241 Passenger side drop. Very noisy "poping" and or "thunking" sound when in 4wd. Possible doner, 89 1 ton with np241, Driver side drop. Wondering if both transfer cases share the same internals. P. S. Yes, the 1 ton was connected to a 400 and mine to a 700 but planning on dropping in a 400. Any assistance would be greatly appreciated. Oh, yea, and one more thing. It is possible to limp a Burb with a blown front transmission seal 200 miles home while using pieces of a turkey pan and bailing wire as exhaust cross-over and cat converter heat shieds. You just have to stop every 30 miles and top off the fluid (saved me a $600 towing bill). Actually, since I didn't go over 55, I only lost about 1/2 a pint of fluid. NOTE, I AM NOT RECOMMENDING THIS TO ANYONE. NO GUARANTEES EXPRESSED OR IMPLIED. Thanks!