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Looking For A Period Correct 1970 Trans Am Automatic Transmission

georgeta70

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My 1970 Trans Am is all matching numbers except for the transmission.

It was upgraded to a 4-speed Muncie in the early 90s, but I am looking for the correct automatic transmission.

Where do I start?

Need help.

Do the transmissions have the last six digits of the serial number on them?

Thanks.
 

Munkyslut

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Turbo 400s have a partial VIN stamped on the pan rail on the driver's (or shifter) side.

Also, there’s a detailed stamped steel tag, and I’m sure you can order repros to your specs.

It’s not that hard to find an early 1970s TH400 with a BOP (Buick, Olds, Pontiac) bell housing bolt pattern to suit.

Don’t get too hung up over finding an exact match.

If your car still had a TH400 in it, even under warranty, it’s not guaranteed that it wasn’t changed. 👍
 

Munkyslut

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Hi, yeah, I'm in England.

Partial VIN generally means just that, only some information & not necessarily matching anything else either.

From memory, so don't shoot at me if I'm wrong.😂

The stamped tags usually start with two or sometimes three letters: B for Buick, O for Old, and P for Pontiac.

The following letter(s) indicatee the application, what siz, and& output engin., A is probably a base engine like a 2-barrell 40, and & a higher letter, like a, D; for example, E could mean an H.O.

Then there are two numbers—just model years after that—and a 4-digit unit build number that doesn't do anything.

The code is stamped into the case on the oil pan rail driver's side, the same as the number stamped onto the engine block.
 

Munkyslut

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I'll see if I can find a case lying about the workshop; I'm pretty sure I got one somewhere.

It'll be stamped into the case number & hopefully, the steel tag.
 
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