I am well into building a 1990 Bronco with the following changes:
-Dana 44 solid front axle out of a 79 F150, with kunckles, spindles, hubs and dual piston brakes from a 79 F250 8-lug D44. Also has 4.10 gears and Detroit tru-trac installed
-Ford 10.25 full floating rear axle out of an early 90s F240 with 4.10 gears and Detroit locker installed
-Fuel injected 460 out of a 1989 F250, converted to MAF
-ZF 5-speed manual trans
-swapped main front engine crossmember in the frame with one from the F250 frame made to accept the 460 engine


The question I have is about rear springs. The front has 4" lift springs for a 79 to accommodate the solid front axle. I have a variety of rear spring choices sitting in my stash of parts and can't decide which to use:
-Original Bronco springs
-F250 HD springs (came on the full float 10.25 axle I am using)
-F250 light duty springs (came on a semi-floating 10.25 light duty 91 F250)


Anyone have experience with putting the heavier F250 springs in bronco? Was it beneficial or did it made it ride so rough that it covered over any increased load capacity benefits?