3 speed OD. what's the final drive ratio?

Okay the 700R is .70, 200R .65 does anyone know what the GM 3speeds with OD are?
I have a 58 chevy with one. Not sure the working condition but curious before I do anything with it.
I know these won't take a lot of abuse but it will be cruiser anyway.

 

Pretty sure those are 30 % OD or .666.

 

Thats close enough for government work its somwhere above 30% and less than 36%
Had a 67 Belair with factory OD

Pat

 

I believe they are .75, I used to have one in my 57 Ford and Im pretty sure the GMs were the same

 

so the only electronics is the solenoid? Mine is all there with the T-handle.

 

The "T" handle is not part of the normal operating system/procedure. It is a lock-out only. Out, it disables the O.D.; in, it enables. The ordinary operation or shifting is done by the solenoid which in turn has access to power only when the governor switch senses speed above a predetermined point.

 

what would be the best way to check out the solenoid? this car has been sitting since the 70's.

 

Might be easiest to bench test it. When I got the OD trans for my Ford I took the solenoid out of it and just applied 6v (yours should be 12v) to the case and the larger wire, I believe mine was blue, the other wire grounds the points so it will shift if it is wired stock. It should "thunk" in and out as power is applied/taken away. You may be able to jumper it with it in the car, but if the rest of the mechanism is positioned so it cant engage, you may not hear it move.