The planetary in a OD works much like the 2 speed Eaton. Once it has made the shift, it doesn't care if it goes forward or backward. I tore up a lot of input shafts and cluster gears, but I never tore up an OD section. I still have a lot of spare parts on hand.

https://plus.google.com/u/0/photos/...9755236946&oid=112636930370126476644

https://plus.google.com/u/0/1126369...1763522338&oid=112636930370126476644

GM and Ford solenoids are a little different. NOS GM go for big bucks on eBay because they fit Corvette.

https://plus.google.com/u/0/1126369...5530771442&oid=112636930370126476644

I even keep complete spare transmissions.

https://plus.google.com/u/0/1081977...2464951986&oid=108197707187186692269

The part where the solenoid mounts is what makes the difference between a Ford OD and a GM OD. It adapts the rear section to the front section.

There is nothing wrong with wiring them according to factory. One of my 56 Fords is completely stock and the OD is factory wired.