Technical Torque Tube Chevy

I've been doing a lot of research but I can't seem to find what I am looking for. I have a '46 Chevy Fleetmaster with a 3 speed and torque tube drive shaft and eventually I would like to put in my T5 but I want to retain my original 6 lug wheels but also have 3.55 gears. Does anybody know if a differential unit from a '55-'57 has the same bolt pattern as the original torque tube rear end?

I also found a '50 PowerGlide rear end which was a direct bolt in so I have the 3.55 gears right now but I'll need the open line for the new transmission so I am wondering if I can just throw in a new diff.

 

I talked with patricks when i started my 46 chevy fleetline. Ill be running a 261/t5 combo in it. He told me to use a 55-62 chevy truck rear end. This will give me the 6 lug bolt pattern and pretty good gears. I run the 235/t5 setup in my 58 chevy truck with the same rear end and am pretty happy. The only main thing idid was buy a rear end leaf spring kit from ch***ie enginnering as i read that once the torque tube is removed the springs are a bit weak. Patricks also has new gears for that 55-62 truck rear end. Hopefully that helps.

 

The above is true, however be aware that the rear end is wider. This can be 'fixed' using skinny tires and or offset wheels.

 

Thanks for the replies. sdrodder, how did the axle line up with the rear springs and shackles? I was thinking that maybe I could take a rear axle and differential from a tri-five and cut the center section of the rear axle housing out of my original and the other axle. Then I could exchange center sections and weld the housing together and convert my rear axle housing to accept and open drive line differential. I hope that makes sense. It's one of those easier done than said things.

 

I know this not might be the advice you needed, but Nissan pathfinder rear should be a close fit, has three rear ratios 3.60, 3.75 and the Diesel is 4.11. Even same bolt pattern/pcd.

It is a very good fit for older Chevys, and I got the advice of running a 1946-1955 car rear, or 1949-1958 truck rear, should be close to perfect fit.
Might be a good fit the other way too.
Just a Ideer to try out.
Down to the pic'n'pull.

 

This is what I'm thinking- A lot easier (and probably cheaper) Than trying to find / repair an original pick-up axle.

 

Thanks for the replies everyone. This will give me a lot to think about and hopefully pretty soon I will get the car rolling down the road with some sort of open drive set up. Eventually I think I will be putting in a 283 and a 5 speed with overdrive just to give it that extra motivation to move and cruise down the freeway. I want the car to look like it came from the factory with a V8. No chrome dress up parts, stock manifolds and valve covers, 2 barrel carburetor, painted small block orange.