I believe i have a 727 transmission but not sure if its a heavy duty set up or not. I was told it came from a truck. I cannot find any clear information thats cut and dry for me; can anyone help? Here are the numbers i found:

above the pan l-side 3640825 m4350 5131

on case casting l-side: 3743103-8

on tailshaft: 18

thanks,

Come on someone can surely help.
thanks,

About all I can tell you with any certainty is it was built June 25.1973. I'm still looking for more info on it.

I think after 69 they stopped stamping the VIN into the bell housing. I have the original case out of my dads GTS, has the VIN stamped. Had a 69 case, no numbers..

Thanks!