So many incorrect statements on my part caused humiliating humbleness.....

Possibly not! Mopar and GM did not share transmissions. A 5.0 (?) Chevrolet more likely used a GM 400 or 4l60, a descendant. Are you sure your engine is not a 5.7, ie 350 CI?

Jaguar used a lot of outsourced parts. None Ford, that I know of. Ford's contribution was money to enhance quality and production techniques.

And Ford bought Jaguar in '89-90, not '87

Cheers
DD