I think I might be onto something here. After watching a ton of tear-down/rebuild videos and looking at diagrams, I think the governor was installed backwards at the time of rebuild.
Here's a link to the video I made. Apologies on the quality. Working under a '57 bird without a lift is no picnic. I pulled the top part of the governor off previously to check the piston operation.
https://youtu.be/xWXLqUnh5Sw
If anyone can confirm that the governor is indeed on backwards, that would really help! Also if anyone has ever pulled a fordomatic tail shaft on a 55-57 thunderbird in the car — that would be good to know if it's even possible.
Thanks for all the help!
Kent