I don't know about length, but I can tell you I had the u-joints out of a '42 3 speed and they were not interchangeable with a '46 4 speed.

I hate those torque tube setups.. had 'em in my '46 1/2 ton and my '50 1/2 ton, and both of them gave me nothing but problems.

an idea is only stupid if you think about it rationally.