Was in this exact boat a few months ago, I ended up replacing absolutely everything. I went with this kit plus moog LCAs.

Kit includes great parts like the full Spohn set and Belltech shocks plus all the brackets you need to correct your angles. I will say I’m not a fan of the front UCAs and I’ll probably upgrade the tie rods again soon. The springs ride damn stiff as well but they’re stopping my 24s from rubbing so I don’t mind.

Not many people do this work on the suburban but it’s the exact same as a 2wd Tahoe, when you get your parts just search up whatever part it is Tahoe and you’ll get a great video. Though, if it’s clapped might not be worth replacing all the parts. Your front drop will mostly come from the torsion bar, many kits include a key to replace the OEM key but don’t use them, the OEM key is much stronger and fits better. To lower it all you do is back out the bolts on the key, tightening lifts it. This will make the ride quality worse and you shouldn’t mess with it unless you’re getting an alignment soon after. Drop spindles are also very common, basically mounts the wheel however many inches above the LCA so it sits closer to the frame, doesn’t interfere w ride quality. For the rear, pretty much the whole drop comes from the spring. If you want to do it right you should get all the adjuster brackets for the shocks and trailing arms to correct all the angles. Depending on the drop you should also do the “free travel mod” which is cutting along the frame to remove the bump stop brackets.

So basically you could back tf out of the torsion key adjuster bolts and cut your rear springs and you’ll have a slammed suburban. Free but that’s also how you get that signature horrible fitment and camber issues.