So here it is. I placed a quarter on one of the gears to show their size.
Robert, what am I going to need for U-joints for this?
as you can see, I'm not just pullin' y'alls chains when I say these things were built for semi trucks. You should see the BIG twin countershaft jobs for heavy hauling
That one there looks a lot like it was setup for a direct mount and not for shaft hookup. You are going to need to remove those big nuts on teh ends and measure the output and input shafts for diameter and spline count,( actually the manual has those dimensions ) that manual I sent you should give you a number of possible yoke options, but there are dozens of others. a 1410 I think is about the smallest joint you will be able to use on the box end when getting shafts built. On mine on the tail end it was a 1550 on the output for teh smallest one ( I'll NEVER break that thing )