Rear suspension question

[bbcmudtruck]

To make a long story short here's my question. I have to switch frames on my short bed. My current setup is leaf spring and the leafs are relocated under the axle with c-notches. My new frame is the usual coil spring setup. Should I spend the money on lowering the coil spring setup on the new frame and switch all of the front end components over? Or should I cut the old leaf spring setup out of my truck and install it on the new frame? Is there any advantage to keeping the truck with leaf springs in the rear over the coil setup? Now with that said, my current rear end is a 12 bolt posi with 3:73's, so I really want to keep that. I could just simply swap rear ends and buy a new rear lowering kit, but my question is, which way should I go? New kit for coil over, or keep current kit and swap over the leaf spring setup? If I should just go ahead and swap the rear ends out and buy a new lowering kit for the coil setup, which kit should I go with? I don't run air suspension and really don't want to. My front end has new 3" drop spindles and new 2" coil springs. I think I would need 7" drop for the rear end for it to sit level, is that correct?