I have a 92 chevy dually 6.5 turbo d.spun the bottem end at 100k pulling a trailer.I want to put in my old carb 454 will the trans bolt up???? my truck is a 4x4  and will the trans still work??I think it is an   900 le?????????Will i need to look for a 700r4  

Transmission will bolt up. If it has a 4L80 though you will need a new ECM to control it with different motor. Sounds like you did not service the 6.5 right because they do not just spin bearings for no reason other than towing.  

pulling a 26,000 pound trailer.hualling 3 cars truck was way under powered over reved motor when downshifting.thank u..........    

26K is too much for any P/U any engine. If it ever got away from you the tail would wag the dog. 30 years ago I had brakes go out on a 23K trailer without warning behind a P/U and it was some anxious moments.