That's right, Barry, but I believe the gears in a 40 to 54 will fit in a 37, 38, 39 transmission case as a set. The input shaft from 37 to 54 has the same splines on it, but the output shaft from 37-39 is different than from 40-54. They have more splines, like the car. So, if a guy has a three speed transmission case out of a 37 or 38 (which are both the same) he can install 41-54 gears in the case and be running a more advanced and stronger transmission than the original transmission, if he uses the front part of the car universal joint. I'm not sure any of this will help, but I have been thru the "the exercise" and know it.
Joe
