How to swap an automatic to manual transmission in a 1995 GMC And no Computer I want to use one from 1973 3 on the tree tranny

The bell-housing will have to be the same--bolt pattern and starter location. The flywheel will have to be changed, in an automatic it's a far lighter flywheel because the torque convertor bolts to it. Then the clutch pressure plate will bolt to the new, heavier flywheel. Then you will have to find a pedal assembly for clutch, cut hole through firewall and all the linkage, brackets and pivot points. Then, either swap out steering columns or much easier is get a floor shifter kit. If the transmission mount is in the wrong place, (different length total from bell-housing to rear output) some fabrication may have to be done (hopefully not, may bolt right up to old mount and crossmember. Then driveshaft length if different..but that's actually easy, a shop can shorten or lengthen, and balance a driveshaft. Last, the final drive..if way different from the auto, the Third Member may have to be made right.

This is flywheel for automatic

Clutch. Not exact ones but demonstrates the difference..the clutch disc must have a flat surface to 'grab'

Update. The swap is complete. The hardest part was converting the steering column. The 95 had a bar the ran all the way across the cab. I had to remove every bit of dash and cut out almost everything. I also had to cut out a chunk of firewall out of two trucks. One from the 95 and one 86 GMC. Weld in the firewall from the 86 into the 95. I had to do this because the 3 in the tree steering column would not bolt in with a 95 set up. The transmission I used was a Saginaw M26 from a 1973 C-10. The steering column from the same truck. I also used the manual brake system and kept it manual steering. No power for me.

It runs and drives well just needs body work and paint. Then it will be ready for the car shows.