# GM (Pontiac) manual 3 speed Transmission



## Josh.AZ.GTO (Jul 11, 2009)

My 70 GTO came from the factory originally with a 455HO mated to a 3 speed manual transmission. It currently now has a pontiac 350 and auto trans I'm assuming a th350 (haven't looked for vin numbers yet to verify). I have been periodically looking in the local adds and on craigslist for a m22 or m21 close ratio, but haven't come across any 3 speeds while searching. 

Are 3 speed transmissions rare or even desirable?


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## Koppster (Jul 27, 2008)

On a gee whiz comment, the 66 I had when I was a kid had a factory installed Ford 3-speed, surprised the heck out of me.


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## PisnNapalm (Aug 28, 2010)

This website may help you identify what kind of trans your car has. Automatic Transmission Identification


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## geeteeohguy (Feb 2, 2008)

3 speed Dearborn built units were the base transmission for the GTO. Automatics and 4 speeds were extra. I've seen a good amount of 3 speeds in these cars over the years. Not rare. The close ratio M21 and M22 gearboxes are meant to be used with a 3.90--4.33 rear gear due to their tall first gear ratio. Not a problem if you run a 455, but if you're running a 350 or 400 with normal gears (3.23 or so), you'll be quicker off the line and better off all around with a wide ratio M-20 gearbox.


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## Sloan66 (May 7, 2010)

I have a complete factory 3 speed unit out of a 70 GTO, trans and shifter would love to sale it. I can send you photos if you like, very nice unit.


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## Sloan66 (May 7, 2010)

Sorry, one other thing it is a muncie. They are cast iron.


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## 70_GTO_JUDGE (Dec 8, 2010)

i would like to buy that dearborn muncie 3 speed


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