I dunno about the spring rates, just some new 4" lowered springs from Early Classic Ent. & garden variety big fat HD gas shocks. Front lowered 2 1/2" using spindles from ECE. 60 ft times were better w/front stabilizer removed. We disconnected the driver's side first, then removed it altogether & got another .010 or so. Even better w/left front shock removed. Small amount of iron(maybe 100lbs) bolted to frame above the rear axle. The long trailing arm on the rear seems to make them launch pretty good, much better than a leaf sprung truck. If you are going w/coilovers it should launch even better. Brian
