In 1980, before the advent of this site and many others like it, I installed a black leather, electric seat from a late seventies Cadillac in my 1965 Chevy C10, lwb fleetside truck. I had no knowledge, expertise or wealth of information from a great site like stovebolt.com, to determine if it would fit. I liked the way it looked and a black leather seat, not to mention electric, was a pretty cool thing to have.
I suggest you set it in the cab and see how it fits and if you like it, properly secure it to the floor board. Not as cool as a black, leather, electric Cadillac seat, but maybe a good solution. Good luck with your project.