Cat385B. Replacing the rear K46 with a beefier unit is a heck of a lot cheaper than taking out a loan or mortgaging your house to buy a costlier machine. Especially when the frame and body can sustain the torque and power output from a far superior trans.
Your second line is my point, but my opinion is opposite. I don't think any machine originally sold with a K46 can handle the tasks of a machine that was originally equipped with the 66. You mention a better plow, for instance. The K46 machine was not designed for, nor can it withstand, a larger or heavier plow. The front axle was not designed heavy enough to handle that.
In reference to your comparison, if the 5 speed manual in my little 4 banger Chevy Aveo took a crap, I might replace it with a used one. I certainly would not replace it with a six speed out of a Camaro or Corvette.
Edited by Cat385B, July 20, 2016 - 03:37 AM.