Here's a suggestion. Use the full sized Jeep Wagoneer, you know..the trucks with the fake wood trim a v8 and leaf springs, front springs. They are only about 1 1/2" longer than the YJs with the same mounting as the YJs. They are soft, supple, very flexy, can carry a load, and will perform very well. I have them on the front of my lwb sammy with much pleasure. I love them. I had to remove the shortest leaf from a 7 leaf pack in order for them not to be too stiff for the 4 cyl. In stock trim, the 6 or 7 leaf packs should be great for the v8. I also have the Jeep Wagoneer rear springs on the back, won't work on a swb sammy, no room. The rears are about 17" longer than the stock sammy springs, about 11" loger than the YJs. If you have a rear bumper tire carrier setup on the back of your sammy, with a sbc under the hood, you should be able to use 2 sets of Wagoneer fronts untouched under the sammy.
Hope that helps.