Need help finding transmission

I have an 1988 Dakota with a 3.9 automatic with o/d (A500). Just pulled the transmission out and the torque converter seems to have locked up or something, the slots on it where it goes into the transmission are broke off. There are peices down beside the shaft on the trans. The peices are lodged in pretty good. Took the pan off and there are soooo many metal shavings. Can anyone tell me if there is any other transmission that will fit this truck??
I just can't see paying $500.00 for a used trans at a junkyard. I would be satisfied to get one where the overdrive doesn't work. I was told that a 727 would work but it won't, the driveshaft is too big for the 727 and the 727 is too short.
Any help would be greatly appreciated as this truck is for my daughter and she is about to get her permit and I want her to learn on the vehicle that she will be driving when she gets her license. Thanks in advance.

you could try and find a 904 (T-6) its a 3speed should bolt up. I dont know about if the drive shaft or trans. mount will work. oh is the truck a 4x4? if so it wont work.

It's 2 wd. Shouldv'e mentioned that sorry.

use a 904/988 transmission and a driveshaft from a 1987 model as none of the 1987 models were factory equipped with a overdrive, driveshafts from manual transmission dakotas of the same age approx 1987-1993 are the same for as the 3-speed auto transmission, keep in mind your gearing will be diffrent as the overdrive was taken in to account when the truck was designed. You can get a cubby hole to replace the od button to eliminate it also from a stick truck or any 1987 model also ensure whather or not the driveshaft is from a longbox or shortbox.

use a 904/988 transmission and a driveshaft from a 1987 model as none of the 1987 models were factory equipped with a overdrive, driveshafts from manual transmission dakotas of the same age approx 1987-1993 are the same for as the 3-speed auto transmission, keep in mind your gearing will be diffrent as the overdrive was taken in to account when the truck was designed. You can get a cubby hole to replace the od button to eliminate it also from a stick truck or any 1987 model also ensure whather or not the driveshaft is from a longbox or shortbox.

I think the overdrive seized up and took out your tranny i know of someone driving on inoperative overdrive units and they end up doing this after awhile.