Confusion about 833 4 speeds

OK, I have a 74 Duster that I have converted to a 4 speed from the 904 trans. The trans that I bought was a OD unit and I am not real happy about how it works. I recently purchased a 4 speed unit from an individual on this forum and have discovered a few issues. First the cast marking are

Bearing retainer: C94769 UF4
Main Case: C97372 A3 and 11-28
Cover: C95664 3 1X5
Tail Housing: c96706K

Date: 10-18-66

I have counted the output shaft splines and there are 26.

The first issue I have is with the output shaft and yoke. I have had my drive line modified to take the 30 spline yoke when I installed the Overdrive trans, but it seems that the 4 speed I just got has a different spline shaft of 26.

1) Is this the same as the 904?
2) Can the output shaft of the 4 speed be upgraded to a 30 spline shaft?
3) If the shaft is changed, can I use the Overdrive units tail housing?

I wish to rebuild the 4 speed and need to know what parts kit to buy.

1) Based on the info provided, Can anyone ID what Syncros and bearing kit I need?

I still have not removed the Overdrive trans from the car, but I am wondering if the bell housing will swap over. The 4 speed trans bearing retainer looks to be smaller that the overdrive trans bearing retainer, but I will not know for sure until I get the trans out of the car.

Can anyone give me some pointers on rebuilding this 4 speed and what to look for. I opened the case and all of the gears look fine, no missing or broken teeth as I can see. I am a Airframe and Powerplant Mechanic and have plenty of gear head knowledge from aircraft engines and that sort, so I am not worried about getting the job done. Just wondered if anyone had some info to help. Thanks for taking the time to read this and hope you can help.