IMHO, I wouldn't do an AAL in the rear. Not after I had one try to kill me when I was taking the rear axle out of a BII. AALs are usually very stiff and thick, so I knew it was in the pack. What I didn't expect was that when I released the U-bolts and was working the axle out.... BANG-CLANG! Center pin sheared and shot off like a rocket and the leaf springs exploded out from under the truck. Nope, don't think I'll be playing with those.
I've done custom leaf packs for my trucks, for my Ranger and choptop I've used various leaf springs to make the packs to suit my needs. BII springs are the softest, Rangers seem right in the middle, and Explorers seem to be the stiffest. So when I needed to build a pack for my Ranger (my DD at the time), I didn't want it to ride like an empty dump truck all the time, but needed carrying capacity since I didn't have my F-150 for a work truck at the time.
Started with a Ranger main leaf, then cut down a main spring out of another truck (IIRC it was a main for a dodge because I got them for free and didn't have any Explorer leafs handy). The key to making for a softer ride is to use the longest leafs possible - thus cutting down a main spring. Then I used the next longest spring I could out of a Ranger pack (IIRC it was the normal leaf below the main), etc. Built a 5-leaf pack and ended up having to use 4x4 shocks in the rear because it gave it a slight lift. Rode really nice down the road too.