Please identiy the suspension type on your truck. If you are not sure what suspension package you have - open the glove box and scan through the alpha-numeric codes. It will read Z85 or Z71 someplace in the mix.
4x4 or 2x4? Z85 or Z71?
Z71 and Z85 4x4's are the same suspension. 2wd Z85 is different than 4x4's and Z71.
There won't be a 'best' answer. And the type of truck will identify what lift and height is available.
1. 2-2.5" coil spacers and shackles for the rear.
2. ^^^^ + a 1.5" body lift for a lil more.
3. 3" body lift (kinda pointless on ZQ8 suspension)
4. 3" spindles and shackles
5. 5" CST spindles, shackles and AAL
Rancho or Skyjacker offers 4" subframe lifts and are good quality lifts, though pricey. They easily allow you to run 33s.
You can crank the torsion bars, but that may involve cutting to clear the tires and doing even more research. It will also stiffen up the suspension some. You might have to purchase keys in the event your suspension has sagged with age. There's a how-to that shows you how to go about doing that.
You can also use the body lift option, which just lifts the body off the frame an extra 3"... Performance accessories offers a 3" body lift.
You can also combine any of the above 3 to get as high as you want. Suspension Maxx offers a couple different body lifts that are smaller than 3". You can run that in combination with cranking your torsion bars to get up high enough to clear the 33s.
As mentioned above, Rancho or Skyjacker full subframe lifts. Parts for a subframe lift start around $1300. Then you need shocks. And wheels to fit the new spindles. And labor.
A torsion bar lift will cost you a few hundred bucks. All you need are 2" rear shackles and a set of torsion bar keys. And rear shocks. Oh, and an alignment. There aren't 3" kits. Torsion bars are adjustable, but the design of the front end has a max height. It may or may not be 3" from where you sit today. Subframe kits are 4".
The link above should help you with the torsion bar lift.
Body lift is an option too. There are 1.5" and 3" body lift kits out there.
More info when you answer back how you want to go forward.
I can find you another how to for installing the torsion keys if you need more help.
Are you at all familiar with torsion bar lifting-in general? I'd encourage you to search through the hundreds of existing torsion bar lift threads. There are a few things you should be aware of. A little background research before you begin will help you with understanding, and the installation.
I am inclined to assume your truck is rusty underneath. That will make for a difficult shackle removal. Often times the bolts and bushing become rusted together. Step one, start spraying a penetrating lube on the shackle hardware. Make sure you can get ALL of the shackle bolts free before you begin. Otherwise you may be stuck with a half lifted vehicle, then problems to prevent you from driving your vehicle while you fight against rust.
Thanks for the heads up....I will research more before beginning. I have never installed a lift of any kind, but am mechanically inclined. I will definately start spraying bolts. Does any one company make a better set of keys, or are they all about the same?
Most keys I've seen look the same....all cast. SuspensionMaxx sells a different style of key. I use their products (keys and adjustable rear shackles). The end result is the same.
Also SuspesnionMaxx gives a discount if you let them know you are a member here. I do not recall the discounted amount though. They are highly recommended, just because they are a great business to deal with.
Generally speaking, the design of the front end has built in limitations to how high you can torsion bar lift. While there may be adjustment in the spring/keys, the suspension and steering components are the limitations. Just something to be aware of when determining our final ride height.
The install is pretty straight forward. No special tools required. To lift 2" rear you'll need new shocks too. You can probably get away on the roads with stock shocks, but there isn't much room for extension.