Hello , I have a White American 60 with out an o/u .  Does anyone know where to find a used o/u from the American series?    I've asked questions on other pages and have found that the Oliver 1655 and White 2-70 used the same o/u unit.  Is it possible to swap one of these in?  I know the American series o/u shifted electornically, and the others where manual shifts.  What should I watch for when buying a used take out?  Is there any way to test them when they are out of the tractor?  I want to thank everyone in advance, information, or anyone with experience on the American series is hard to find.  Thank You  John