I've been looking at solutions as well and think I will order the appropriate year Mustang cables for the calipers than see what I have to do to make everything work. I do intend on losing the A Body handbrake and going to a pull-up brake mounted by the buddy seat.
thats what i did. but the original Mustang e brake handle i don't feel too good with. It works perfect but doesn't feel good. Used also the original Mustang cable. You Need to do a small bracket were the upper part of the cables are ending.
