I have shackles in the back. The blocks and shackles should get you 4"

 

Yes, if you go 6" you need to notch.

 

Ok cool, thanks for the help! Someone said something about hangers, DJM said you can't do hangers on a Z-71 b/c they are different than on 2wds.

 

I am doing hangers and shackles to get 3-4 in back.

 

How far can we drop the front of these 4x4's before CV angle becomes a concern? Right now, mine are angled about the same that they were before, but only in the other direction (axles used to be like this:
[wheel / diff \ wheel] when looking from the front, now they're like this

[wheel \ diff / wheel] if you get what I'm trying to represent here...slashes are the axles)

Also, FWIW, I used to have a vibration from about 60ish to 75ish mph that went away AFTER the drop Alot of guys have to use pinion angle shims to correct a vibration they get after lowering, yet lowering cured mine (I had the same vibration with two different sets and sizes of tires before hand, so that wasn't the issue...maybe I corrected a pinion angle issue I had from the factory )

 

Does anyone else have a problem with the stoppers hitting the control arm? I lowered mine just about as much as i could in the front and I'm about half an inch from the stoppers, so torsion keys would be no good to me... anyone else?

 

From what I've read here, and confirmed by looking at my own vehicle, the the lower control arm is actually supposed to rest on the stopper. The stopper actually acts as part of the spring rate. When I first did my drop, I trimmed my front bumpstops by eye prior to the drop, and when I was done, they weren't touching and the front end was kind of wishy-washy. So I bought new GM bumpstops (that are rubber while my originals were a harder material that I guess the Z71's got in that year...the part number I used I got on SilveradoSS.com), and I trimmed them so that they're just touching the lower control arms at rest. Now the front end feels solid and even feels like it corners better (feels like I put a bigger sway bar up front). It's a bit harsh over bumps, especially washboard roads, but feels and corners well otherwise.

 

Oh, no kidding? Never heard about that... today is actually going to be work on my truck day lol... so I drop my front end and see what happens... thanks!