3 speed transmission identification. *HELP*

[Lightfoot]

I recently picked up a 3 speed to use in my '67. I was told it came out of a 1966 Pontiac Tempest with a 6 cylinder, but what does that make it? Could anyone tell me?

Casting #'s
Case- 3858986

Cover- 3858992

Tail- 3878886

[ol_skool_chevy]

It really does not matter what the Trans come out of, In basic terms its a GM 3 speed. They were use in many applications. what's more important is the gears. On the tail shaft are grooves from none to 3 groves. Gearing is as follows. wityh No photos it can be somewhat difficult to ID.

also is there a back up switch?

Saginaw 3-speed 1st 2nd 3rd
No Lines (grooves) 2.85 1.68 1.00
1 Line (groove ) 2.54 1.50 1.00
2 Lines (grooves) 3.11 1.84 1.00
3 Lines (grooves) 3.50 1.89 1.00

[Lightfoot]

Thanks for the help. I believe mine has no grooves. Which one would be best for a sbc and 3.73 setup or does it really matter? Ill try to get a picture of it soon.

[ol_skool_chevy]

In my mind it does not matter if your using a SBC unless your talking about how strong the trans is and the Propose its being used and the weight of the truck your putting it in.
Some might say the 3 speed is not a very strong trans. I would have to agree. But if you only using it for daily driver it should be a nice little around town trans.
No groves is the 2.85 1.68 1.00 trans.
Its will be some what faster to start off then say the 2.54 1.50 1.00 but in the end they all are 1:1 on the Hwy. I would say with a 3.72 read end it would be nice

[Lightfoot]

Thanks for the help. I plan on cleaning it up and getting a hurst master shift. I got the transmission for $50 at a swap meet.