# What Transmission is in my '64??



## Al T (Mar 15, 2010)

Can someoine help me to identify the transmission in my '64?? The engine is a YJ code 1966 421 tri-power. This link was identified in another post Automatic Transmission Identification and it got me wondering. I had assumed it was a 2 speed as the car is a column shift (for now) and has the 2 speed shift plate.......... but if you were putting a tri-power 421 into a GTO, would you put a 2 speed in it??? I crawled under the car tonight (yes on stands) and took a look. The pan has 14 bolts and does not match anything on the link mentioned above. What transmission is in my car????










Thanks in advance

Allan


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## 05GTO (Oct 6, 2004)

If the pan extends under the vacuum modulator and above the cross member which would be at the top right of the picture it is a 2-speed st-300 which is correct for 64, 65 and 66 GTO and up to the 69 tempest, lemans and firebird,


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## nedorama (Sep 13, 2010)

Usually, those 2 speeds were the wrong 2 speeds at an speed... I swapped mine out with a 200 4R from Art Carr and new Eaton Posi and have been very happy. 

Caveat - my LeMans already isn't 100% stock and it's my daily driver, so after adding disc brakes all the way around, keeping the original drivetrain wasn't as important to me.


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## Al T (Mar 15, 2010)

05GTO said:


> If the pan extends under the vacuum modulator and above the cross member which would be at the top right of the picture it is a 2-speed st-300 which is correct for 64, 65 and 66 GTO and up to the 69 tempest, lemans and firebird,


Thanks! I didn't even notice the st-300 wasn't on the link.

Allan


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