Im only running a 2 inch lift but got the Tuff Country HD springs because they have the highest spring rate I could find. If you do a new leaf spring in the rear you technically wont be a 1 1/4 ton payload anymore but will probably ride a lot better. Theres altoa brands that are good superlift, skyjacker, Tuff country etc ive run all those lifts on different trucks and there all good to go. Youll need a new steering arm and probably have to have the drive shafts lengthed if you go 6 inches. Wouldn't hurt to get new brake lines. I know skyjacker makes some nice stainless ones wich would be a nice upgrade over the old stock rubber ones. Not much else that youd need. A complete kit should come with **** near everything you need. Springs, shocks, u bolts. One thing I like to do is lube the new spring bushings with lithium grease to avoid any squeaking while they break in. Make sure to soak the old bolts in wd-40 or pb blaster a few days before you plan to takt it all off. Do it every night for at least a few days prior to help them break loose. I know the steering arms can be a pain to get off sometimes if that's the case smack the side of it with a sledge and itll usually break free. Hope this helps. These older leaf sprung trucks are real easy to lift if you got a jack and stands and a couple of hours. Oh yeah might need to check the ebrake cable for slack if you go up to high.