I believe you can get a 8.8 out of a foxbody/notch back. i think they are 4lug also, however i dont know all the specifics as lug pattern, total length, I also think you have to mod the spring perches for leafs.
i put 3.80 gears in my 8 inch on my 68 the mini spool is the same for a 8-9 inch, it was really cheap 100 bucks for the shop to do it, or if you have a dial indicator you can do it yourself. i would find an 8 inch who takes the time to count all of the lugs on a car anyway??, i guess some people do.