For my rear suspension, I put new heavy-duty leafs on the back - (and used rubber in the rear as well - *blush* ON the rear, I mean) - they were a tad shorter than stock (as I was trying to lower the whole car).
I had to add air shocks though, 'cause with my fat tires, I tend to catch JUST THE EDGE of my firehawks on the outside edge of the tires when I bounce 'er. I guess I'll have to ask how folks make that stop at some later point. Alas, probably will have to go with slightly thinner tires...or roll the wheelwells a tad - though I wanna use my waiting NOS wheelwell trim!!! (which was bought from John's Classic Cougar back in the day when they could still be had for $40 each - sheesh, wish I woulda bought a FEW sets!).
I had a new locker put in the rear too, and am happy with that (except for the clanking noise - that I was told is 'normal' - when I turn right after running the car for a while). The sad part of that is though, I had the work done when I was going through a mostly-drunk stage in my life, and lost the paperwork, so I don't know what KIND of locker is in there, NOR what the ratio is, even. I guess I'll have to be a little more cognizant next time...*blush*