Transmission has an aluminum case, short output shaft and large bearing retainer. Case numbers C13303A, tail shaft C13386 1, build date is 1976. Is this an overdrive tranny? Can I change to a long tail shaft and use in a b-body?
It is a NP833 O.D.
to make sure mark the input shaft and front bearing retainer so you can count the rotations of the input shaft compared to the output shaft revolutions in both 3rd and 4the gears, in 3rd gear the input and output shafts should turn identical, in 4th gear it should make the output shaft rotate about 1/4 turn more on the out shaft compared to the input shaft
I've own a bunch of different NP833 tranny(body styles and years) including two of the A body size O.D. tranny which both had the smaller output shaft like the 904 trannys used
As fars a bolting it in and using in a B body you probably better of looking for another NP833 O.D. tranny out of a pick up and van the use the best parts out of both trannys with the pick up longer style output shaft and tail shaft housing so it will bolt in to your car.
I put one of those in my current street car, 1966 Dodge Coronet Deluxe two door sedan replacing the slant six and 3 speed on the tree with a 440, NP833 O.D. and a Dana 60 with 3:55 gears
BTW I have one of those pickup, van O.D. 833 tranny that is in excellent shape with the stock type Hurst shifter in the tranny and rear end parts forum for sale on this site with pictures of it and 3 other 833 trannys I'm selling