Transmission / Overdrive: Switch back to 53 tranny?

[Studebecker]

Long ago I had a guy talk me into buying what I think is a 1955 transmission to replace the one in my 53 Commander Coupe (I unfortunately tossed the original tranny). It's a three speed with overdrive. He said it was basically the same. It works fairly well, though it pops out of second, but the overdrive has never kicked in. I am pretty sure that's because it's got a 12 volt solenoid and my car is 6 volt. In fact I tried kicking it in with a 12 volt battery and it works fine. Not so with my 6 volt starter.
So, my question is, should I look for an original 53 transmission or stick with the 55 and get a different solenoid?

[Tom Bredehoft]

Find a 6 volt solenoid. Assuming the wiring harnes is as original, it should work fine. 1955s were 6 volt also. But that's not an issue.

[gordr]

Could also be a bad governor, bad relay, or fault in the wiring. Throwing away the old transmission was a big mistake. They can be rebuilt, or yield up useful parts to repair somebody else's transmission.

If the transmission DID come from a '55, it would be six volt, unless the car was changed over to 12 volts. If six volts direct from the battery won't pull the solenoid in, then you can probably assume that to be the case.

[RadioRoy]

The 53 and 55 transmissions are identical. So says the parts book and I believe it.