I am installing a 6" pro-comp suspension lift on my 1500HD. I was wondering if anyone has researched the effect of using tapered lift blocks on the rear alignment. Normally, the lift kit suppliers will provide a tapered rear block. This will rotate the rear axle up, to give you a better drive line angle. In a rear steering vehicle, this will adjust the caster angle, which our vehicles do not have an adjustment for. An option for this lift is to substitute a 3" flat block, for the 4" tapered block (along with an add-a-leaf). This should keep the alignment correct, but does anyone know if it would cause drive line binding? I hate the 'Cali' look, of having the front end higher than the rear, so what if I found a 4 or 5 inch non-tapered block? Has anybody that has installed a lift had any problems with using a tapered block? Do you know if there were any problems with the rear alignment? Thanks for any help that you may give.

Gary

There was a place in Cali that has done many lifts on our trucks. it's in a post somewhere here. If you haven't tried a search give it a shot. I will take a peak also. If you get the lift installed do we have some before and after pics?

With QS, anything more than 3", is asking for headaches.

No offense, but save your money to do a lift right. Get rid of the block.

"With QS, anything more than 3", is asking for headaches."

I have seen posts where people with Denalis had problems with vibration after installing a lift, because they have full time four wheel drive, but I haven't seen anything about the 1500HD's having any problems. Do you have any links that anyone has posted about problems with lifts on this truck, other than the normal problems that people have when lifting trucks?

The lift kit from Pro-Comp actually says that it is for Quadrasteer. It is the only one that I found that says that it will work with quadrasteer. All others don't mention it, or specifically exclude it. Since Pro-Comp says that it will work with quadrasteer, it makes me think that they have installed a couple and that they work.

"No offense, but save your money to do a lift right. Get rid of the block."

In most cases, I would agree with you, but it is not always the best choice to go with a spring with higher arch. In my research, I believe the Superlift website or installation manual states that the stock spring is very high quality and that it is a waste to replace it. Also, many trucks come from the factory with lift blocks, so they aren't as bad as they are made out to be. Yes, you may get some spring wrap if you have large tires and lots of HP, but you will get that with new springs as well, just at a milder level. The new springs are often set up for a comfortable ride, and since I tow, I didn't want to take the risk of spending $600 and have the rear end squat too much.

G-

I'm referring with quadrasteer(QS). Yes, I've seen the ProComp kit, just like I've read articles with 12" lifts being used with QS. I believe those are sub-frame lifts. The lack of links you'll encounter dealing with 6" and higher lifts for our trucks used as a daily driver should be enough to tell you something. I'm not saying it can't be done, but that's whole bunch of money to overcome the dynamics.

Second is I guess you won't need your warranty to cover any mishaps. You think the dealers give us a run around now, even if we just install larger tires, whether the tires are in spec or even come as a factory option. Wait till they see you come in with a 6-inch lift.

About the ProComp lift, to be specific, it says it's "compatable" with QS, not work with it.

Skyjacker's 3"-4" lift is the only manufacturer thats been tested extensively and works with QS. Search this topic thread and one member has it.

IMHO, any lift manufacturer stating to use the block to keep the spring is very irresponsible. Ironic that Superlift cares about saving the leafpack because of it's high quality, but using a block speeds up leaf sagging, decreases load-carrying ability and as you mentioned can cause axle wrap. If you still go that route, make sure you go with steel blocks, aluminum blocks are prone to breaking.

As far as blocks being supplied by factory, it's a matter of economics, plus we're talking approx. 2" block. Cheapest route to supply trucks with different heights because of the different uses. That's why you'll see a 1500 series 2WD without the block and a 4WD with the block, using the same or similiar leafspring.

Because the QS steering assembly has only 2 gear ratios that it's programmed to work with, manipulating the gear points of the transmission is your only option to compensate for too big of tires, if installed.

Good luck with it and keep us updated.

This message has been edited. Last edited by: Quadrant,

It is installed. There are a lot of pieces and it took me a lot longer to install than I thought that it would. I need to get the exhaust re-routed because the drive shaft goes right through the middle of it. I drove it last night and it felt fine. It was almost anti-climactic, as it really didn't feel any different, except that it does need an alignment. When I get a chance, I will get some pictures.

G-

Congrats Luchenbach! Looking forward to the pics.

I'm looking at doing the 6" lift on my truck as well. How has the ride been after that alignment?

It's awesome.

I got the adjustable MX-6 shocks, which I would recommend. The soft setting is good for low speed off road driving, but is too mushy for street driving. The 3rd setting is really good for street driving. The firmer settings are good for towing.

I have not had any problems, and I have used the truck pretty hard. I only have about 15000 miles on it, but a lot of that has been off road miles and towing trailers. I spent two weeks hunting in Nevada, where the unpaved roads go on for hours. I have had to have it realigned once, but it was because I hit a huge rock and it would have knocked any truck out of alignment.

The pro-comp kit comes with a 4" tapered rear block and an add-a-leaf, which will add maybe 3/4". This will give you a level truck. The tapered block is not good for the quadrasteer since it changes the alignment, so I looked around for a non-tapered 4" block. Superlift had a part listed, but when I received it, the hole size was too large. So I had to go with a 5" non-tapered block, which I used alone, and then with the add-a-leaf. I have a 400 pound steel campershell on my truck, and I tow a lot, so I kept the add-a-leaf with the 5" block, which keeps the rear end a little higher than the front. I had to have custom U-bolts made to account for the additional 1" lift in the rear, and I did get the rear driveshaft carrier bearing spacer, from Pro-Comp, to keep the drive-line angles reasonable. The rear alignment came out perfect with this set-up.

Ideally I would like to put 37's on the truck, and change the gear ratio's to 4.56's or 4.88's, and put e-lockers front and rear, but I don't know if it's worth $4500 plus the cost of the tires. Maybe one day.....

Gary

Gary,
I'm glad to hear the lift worked out great for you. Do you have any pictures of your truck before and after? Are you running dual shocks up front?

Up in Reno, you guys get a fair share of snow right? I'm actually planning to move to the midwest and I'm not sure how a lifted truck would handle in snow. Being from southern california, my experience in snow is pretty limited.

What size tires are you running on your truck now? Have you regeared or you still running the stock gears? Any big differences in fuel economy? Is it possible to regear the rear end to something lower than 4.10? From the other post, others have said that the computer will only recongnize 3.73 or 4.10.

I don't have any pictures after the lift kit was installed. I will try to take some and post them soon.

We went Christmas tree hunting this year, and encountered a lot of snow. We were following a small SUV and a standard 4x4 truck that had chains on the front. I had the 33" Pro-Comp Mud Terrains on my truck. We got to an area that only had a truck or two pass before us. As soon as we hit a steeper hill, the SUV stopped and was stuck. The chained truck went around the SUV, with a bit of drama as it nearly slid into the SUV when the rear end slipped. I blew right threw with no drama what so ever. My wife was very impressed, and stopped whining about all of the money I spent on improving the truck.

As far as driving on the highway with snow, I don't really know as all of my trucks have been lifted, and it is tough to compare vehicles because the snow is always a little different, as some will be wet or more packed, or icy.

I use a Hyper-tech hyperpac to recalibrate my tires, and it will calibrate for a different gear ratios as well. The stock computer was only calibrated for either 3.73 or 4.10 gears, but the hyperpac will handle different gears. I have not changed my gears yet, and probably will not until I get my 37's in about a year or two.

I did not do the dual shocks up front.

As far as the fuel economy, I am not sure as the truck was not broken in yet when I changed to the 33" pro-comps, so I did not get good numbers before I changed to bigger tires. My gut feeling is that the 33" pro-comps dropped about two MPG. The 35" BFG all terrains get better gas mileage than the 33" pro-comps, by at least one MPG. I have 4.10 gears, and the RPM's at highway speed is at a much more desireable level with the 35" tall tires, when I am not towing. I lose a lot of power when towing with the 35's, due to the lower effective gear ratio with the 35's.


Gary