How to ID transmission in a 1977 GM V8 350 280TRS

[EMTJEEP]

I have a 1977 Formula/Thunderbird 20-CL with a GM V8 350 280TRS. How do I ID what transmission it has coupled with it? I couldn't find any serial numbers around the transmission. Don't know if the serial numbers from the engine and drive will help but I'll post them up. Drive-4645516 Engine-4499399

 

[Bt Doctur]

post some pics ,could be a merc trans or a velvet drive 71 or 72 series

 

[alldodge]

Could also call Formula with your hull number 800.736.7685