I live in northern Chicagoland and need a recommendation for a shop to have my auto. trans. converted back to a manual. My 69 GTO convertible has a Turb. 400 auto, however, according to the PHS records, it should be a 3 speed manual.
Keep in mind that the 3-speed manual was the base transmission and the 4-speed or the three speed TH-400 was an additional option/upgrade.
Does the engine code agree with a manual transmission car?
I would be looking for tell-tail signs that the swap was actually done as it is possible that the documents may say 3-speed manual when in fact it was fitted with a TH-400 from the factory.
Verify that the TH-400 is not original. Look for a 2 letter code and you should find the last 8 numbers of your Vin stamped on it. If you find your vin, then you know it is factory installed.
Look for tell-tale signs that a manual trans was installed. My guess is that most would not remove the small bracket found on the frame for the clutch cross-over shaft or even the ball on the engine that supports it. If you pulled up the carpet, you would see the holes for the console mounting plates if equipped with a console.
Swapping to an auto would require a lot of changes and even hurt the car's value, so it would seem odd to go from a manual trans to an auto, so do some verifying first.