Smaller block in the rear and lower your torsion bars until it's level. I would keep a thumb space in between the jounces for a great ride.

 

Pretty well every lift manufacturer will list a lift height of their kit. The catch here is how much longer is the lift companies knuckle compared to the OEM knuckle.
For example, some companies will offer a 6" lift and use a 6" longer knuckle. In the case of this lift you cannot go any lower than 6" because of the 6" longer knuckle, however you may be able to go higher by cranking your T-bars.
Another example would be Cognito's 4-6" lift. Now this kit uses a 4" longer knuckle and to get the truck up closer to 6" you have to crank the T-bars. The lowest you can go with this kit is 4".
Rule of thumb, The minimum height any lift will go down is based on how much longer that kit's knuckle is over the OEM knuckle.
The best thing to do is if you find a lift you like, no matter what amount of lift is advertised, find out from the lift manufacturer how much longer their lift kit knuckles are over stock and that measurement will give you the minimum height your truck can be set at safely.(CV's level)
Most lift kits will usually have a shorter knuckle length than the advertised lift, which is why a lot of guys can drop their 6" or whatever lift lower than the advertised height. Also, the Sub frame brackets are extended the same length as the knuckles.

 

By knuckle do you mean spindle? Or drop box? Not understanding your terminology here since I'm pretty sure most of these kits just come with drop down brackets/boxes/cages and utilize factory spindles.

 

Great write up Jacq. Very informative. I am looking to lift my truck 4" but I want the best ride I can get. I have the keys turned up to clear 32's but I hate the ride.

 

Thanks, If you want the best ride from your lift make sure your CV angles are level and don't crank up the t-bars once it's installed. That way your suspension geometry is pretty well the same as stock. When you start cranking up your T-bars, the ride starts to suffer.

 

Another member said to get a 6" lift and drop it to get the best ride. I was looking at the cognito 4" but I wonder if a dropped zone 6" would be better?

 

So if I find that I'm comparing a lift that is advertised as a 4 inch lift and the knuckles are 4" longer vs. a a lift advertised as 6 inches with 4" longer knuckles, are there any reasons to go with the 6 inch? Or are they pretty much the same?

 

They are both essentially the same. If you buy a 4" lift that uses 4" knuckles then in order to go higher than 4" you have to crank. This goes for the advertised 4" lift or the one that advertises 6" but only uses 4" knuckles.
That being said, and I'll use the Cognito 4-6" kit as a reference.
Cognito advertises this lift as 4-6" using 4" knuckles, so if you install the kit and leave it at 4" your CV's will be level and your ride will be good.
However, if you decide that you'd like to be closer to 6" then you have to crank the T-bars which will increase the angle of your CV's and UBJ's which will make your ride a little more harsh. The way Cognito gets around this is they recommend you use their UCA's to compensate for the increased height. The added UCA's, which are slightly longer than the OEM UCA's will correct the lousy UBJ angle and make the ride better, although not as good as it would be sitting at 4".
The caveat to this is, should you decide one day you no longer like the 6" of lift because the Kids/Wife/Girlfriend, whatever has a heck of a time getting in your truck you then decide that you want to drop the lift back down to 4", you may have to remove the aftermarket UCA's because if they keep the UBJ shafts straight at 6" of lift they may not keep them straight at 4" which is mentioned in the above thread.
What ever lift you buy and if you keep it at the same height as the added knuckle length then there is no need to buy aftermarket UCA's because essentially your suspension geometry will stay the same as OEM.
Also, what a lot of people might not think about is if you buy a whatever height lift you have to add a few inches more to your truck height because anyone who buys a lift is surely going to buy taller tires.

 

No because one is a true 6" and the other one you are going to have to crank the torsion bars so you lose your ride quality.

 

Just installed my 6" Fabtech on my brothers truck and set it around 4.5". Only thing that surprised us, and that you should be mindful of when buying a lift, is if you are looking to decrank the torsion bars I would not recommend buying after market UCA's ( upper control arms) They are very popular and help out with the upper ball joint angle when you crank the lift up. This, however, has an opposite effect when lowering a truck and there are several threads where people are putting their stock arms back on because of this.

 

How does it ride? What shocks are you running? Can you post some pics?

 

Yeah I will try to get you some in a bit. It has Bilsteins front and rear and I can get you the PN if thats what your looking for. As for ride, I have to say it rides amazing and he loves the height of it. I think he is running 33's. So it doesn't rub and basically looks like how the truck should of when Chevy/GMC originally designed it.

 

Thanks sounds awesome. Why did you decide on fab instead of the cognito or zone?

 

Lowering keys with my 6" zone and 2" blocks

 

I've been looking at the 6 inch zone. So to make that lift 4 inches, you had to buy different keys and different blocks? Were you able to get them to supply these or did you have to buy them separate?

 

Here's a quick one in has 2" blocks also

 

Subd

 

Great write up!^^^.

 

Do they make a lift with like 2 inch knuckles??

 

I've never heard of one, but who knows. If they don't make a 2" knuckle I would think the reason is that you can almost achieve 2" of front end lift with a leveling kit if you do it right and you don't have to tear apart the front end to get it done except to replace the UCA's(Doing it right).

 

No such thing as leveling the truck the right way with a "f**k up your ride kit".

UCA's are a joke, they just simply allow you to go even farther away from factory spec angles.
Just my opinion.

 

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Lots of good 'tech' info in this thread.

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This, so much research eliminated just by looking at the first page of this thread.

 

You guys that have lowered the 6 inch lifts. What jounce bumpers are you running?

 

The OEM z71 ones from the nbs trucks ride great and last longer.

 

I don't know why I cannot edit my post..... But, I also forgot to mention that an actual 4" lift may also have shorter sway bar links. Does this matter much....don't know, but shorter is potentially stronger and less flex given the same OD and material.

I did call Zone asking about dropping their 6" myself because of many threads I read on the internet and the price of it. They basically said it is not ideal even though they know people are doing it. They recommend the BDS 4.5" if you want to do this since it is what they can indirectly sell (sister company). It is not as much about the CV's as the other angles it puts out of wack (upper ball joint, tie rod joint, bump stop, etc). Their 6" kits diff drop is not a true 6" but a little smaller drop, so dropping things down a half inch or so would probably give you level CV's without throwing the rest off much though. You might need to trim the bump stop a little.

 

Sooooo, this probly won't work but has anyone ever put a 4 inch knuckle from another manufacturer on? I have the same issue fabtech 6 inch that I want to bring down. Does anyone know if I can get the cognito 4 inch knuckle to work on the fabtech lift? Without massive fabrication. I am thinking those parts probly have the same locations and sizes for other hardware cause they would have to fit stock parts. But again I don't know.

 

The only way it would work is if your Fabtech Knuckle is 4" longer than stock like the Cognito Knuckle. If the Fabtech knuckle is any longer than the Cognito knuckle then it's not going to happen because the subframe brackets on your lift kit drop down the same height as the knuckle length. Also another problem you may encounter is that each lift kit manufacturer builds a certain amount of tracking distance which means front tracking can be anywhere from 0.5" to 1.5" or more over stock. Every lift kit manufacturer supplies a CV spacer and depending on your front tracking distance that determines the thickness of this spacer. So your CV's may be too long or too short.

 

HI I'm new to the site. I'm on my second duramax/lbz. This one has a 6 inch full drop lift turned all the way up in front and 4 inch angled Block in the rear. Clamped leaf springs and adjustable shocks. Truck is riding on 35x12.50 on 20x10 wheels. I'm looking to lower this lift down to get angles corrected and better ride qaulity. I've researched seveal options and I'm thinking of 33s and 2 inch block in rear? Turning torsion keys down in front to level. I feel I have right idea, but I'm 100 that something will be off because I've never dealt with a lift.