I’ve built my own leaf packs before, one of the keys is to keep the leafs as long as possible if you want a better ride, lots of short leafs carry a lot of weight without sag, but it will ride like the axle is welded to the frame. Granted, too many leafs of any length will ride hard, but longer leafs allow more flex. My first Ranger I rebuilt the packs by cutting the eyes off a set of mains and putting it between the main and the first leaf in the standard pack. I also added another leaf in. Made my 2wd sit like a 4x4 with no blocks, rode decent and didn’t care what went in the bed.
My F-150 I got some F-250 packs and did much the same thing plus put 1 ton rated coils in the front (progressive rate and coil over helper shocks). Rides a little hard but I can put one ton in the bed and it doesn’t look like I have anything on the truck, sits near factory height at that point. Takes about a ton and a half or so before it starts looking like I have weight on it. Which is exactly how I wanted it, it’s been my hauler for quite a few years now. It sits empty like a 250 or lifted 150.
My choptop I did the same kind of thing but because of how light it is, it rides harder than I’d like. At some point I’ll do something different. I used Explorer packs to build that by adding two extra leafs. With a shackle it got me about 5” of lift over factory