Standard shift tranny swapping

[DailyDato]

I have built many automatics, and most have a swapable output shafts, say swapping between 2wd and 4wd parts, are the out put shafts swapable in a datsun standard shift? Can i use the case of a 620 4 speed, and the gears out of a 720 5 speed, with the input and output shafts of the 4 speed and create a tranny that will be the correct length i need to have a 5 speed seeing that a tranny the right length is a lil hard to find in my area?

[izzo]

Measure the trans length, some are short tail some are long. try and find one thats the same length. Yes, you can take a 4 speed 620 bell housing and put it on a 720 5 speed. Sometimes it requires drilling i think (for a shift fork?)

 

Keep the gear off the 4 speed to toss on the 5 speed so your speedo stays the same.

[DailyDato]

I have five trannys right now, and they are an array of ones which will work, but all have highly varying length, I don't mean to just use the bellhousing, I was wondering for the whole case, bellhousing and tail shaft, and say maybe just swap the gears from the 5 speed into the 4, but didn't know if the shafts are removable from the gear sets

[izzo]

Wait for datzen mike to see this thread, he's a tranny guy (lol)

[DanielC]

I am pretty sure you cannot put 5 speed guts inside a 4 speed case. As old as these cars are, somebody would have done it by now.

 

I have put a long 5 speed in a 521. As far as the length goes, shorten the front half of the drive line, move the mount on the bracket that bolts to the frame cross member, and cut a new hole in the floor for the shifter.

The three pieces that need welding (driveline, mount, floor cover) can all be unbolted from the truck, and put on a bench so bad welders like me can do it under ideal positions.

 

You will need a yolk that fits the back of the transmission you are putting in. I believe you can use a stock u-joint to mate the new yolk to the shortened driveline.