Have a read through this thread? Do you have a 4 bolt side cover or a seven bolt? There were two different versions for this tranny. Actually they are pretty tough transmissions. The only thing that is getting a bit hard to find is the electric solenoid and governor switch for them. I have the seven bolt later tranny with synchro first and think it was my best addition to my GMC with 305E V6.
Regards,
Steve
New Orleans

https://www.stovebolt.com/ubbthread...Main=103573&Number=712648#Post712648