Nope it wasn't a 904 but probably a built 727. Never really thought about it in 1978

 

Even back in 1978, 904 internals in a 727 transmission case wasn't out of the norm for the faster Super Stock cars. Pro Trans will build one for you still today.

 

There’s also the Tremec TR-4050 which is what’s used in Mexico in place of the NV4500.

 

now that would be the way to go if I could find one that mates up and in my price range. Apparently you can get them with PTO too. Don't know what I'd use it for but still pretty cool. Put a plow on there or something maybe

 

They’re supposed to be a direct bolt up in place of an NV4500 (within a half inch of identical length).