Lift options for 2002 Suburban 2500

[Polymath]

I've been doing some research into various lift kits for my 2500 'burb. Suffice to say there are a lot of opinions and not a lot of facts that I can easily find. I'm hoping there are a few folks here that can provide some wisdom on lifting a 3/4 ton GMT800, staying with IFS, dealing with the autoride BS, and what (if anything) I actually need to do about the autotrack TCase.

The vehicle is a 2002 suburban 2500, 8/1, LT, AutoRide, AutoTrack, 4.10 gears

The goal is 33" or 35" M/T style tires with 3" to 6" of lift. I'm leaning about 60/40 toward less lift w/ 33's. Can't make up my mind. It must maintain reasonably good highway manners as the wilderness areas I frequent include stretches of 80mph highway to get to. I also plan to tow a popup camper which weighs nothing compared to the tow rating of a 3/4 ton vehicle. No rock crawling. Just snow, mud, and deep rutted out designated trails. I'm not interested in lifting it just to make it taller. I want it to ride better and perform better, knowing that big tires and a lift will degrade the high-speed and towing performance to an extent.

SAS is beyond my skill / comfort level and is basically a $10k job to complete, so it's out of the question unless someone can convince me it's just that damned much better at what I want to do.

I've been looking at the RCD (Race Car Dynamics - the kit ORD sells) and BDS lift kits but i'm open to other suggestions.

• AutoRide: I see many kits mention that they are not compatible with Autoride. I assume the fix is to delete Autoride which i've seen some videos of and it seems pretty easy. Can anyone confirm if that's the only reason and that mechanically everything will fit all the same?
• Autotrack: I've read some folks saying you have to replace the front drive shaft with any lift over some arguable number of inches. What's the deal with that? Should I plan on adding a front drive shaft into my budget for this project?
• CV shafts: Some people have said they break too easily, some lift kits have lowered differentials to correct the angles, some people use longer shafts from later model years. What's the deal? If I lower the diff does it get rid of the problem? Are the shafts just weak, or are people over-stressing them through bad geometry?
• Exhaust: How do I know if I will need to modify something there? RCD says "some models" and BDS says only gas models need it.
• Gears: I've seen people argue either way. I'm tempted to think that with the 8.1 motor I won't have issues running 35's on 4.10 gears. Anyone have experience on that combo?

Here's the burb, because pics are cool...

 

[Blue85]

Well there's practically whole forums devoted to what tires on what wheels clear NBS with different lifts, so you should be able to find what you need there. Does that front bumper give you more clearance? I would think the limiting spot is the rear of the front wheel openings and narrow tires with wheels backspaced to tuck in help.

I think 33's can be made to work with almost no lift. My '03 2500 burb is on 31.6" tires now and there's extra room even though I haven't adjusted the torsion bars for the 6.0L-->8.1L swap yet.

Differential drop is always a compromise. The lower you go, the better it is for the CV shafts and the worse it is for the driveshaft. I wouldn't lift more than 2" and use the stock differential location and half shafts. Can't you achieve your goals at 2"? Having wheeled a NBS Yukon XL, I would put priority on removing the running boards and making some kind of skid plate for the giant plastic gas tank. Anything you can do to increase the pathetic stock IFS wheel travel will make your adventures more comfortable, but also increase the complexity of the build. A truck that rides at maxed out height all day to clear the tires would perform better lower with smaller tires.

As for towing, a pop-up is not tough because of the smallish aerodynamic cross-section. But, I question how capable of a vehicle you need for places a pop-up can be dragged.

 

[Polymath]

Popup is getting a lift too. New frame with a front porch for toys, a 3500lb axle, and some leaf springs. It'll have plenty of clearance. My poor old blazer just found itself in 3rd place for my time. lol.

The burb is currently on 265/75 so about 31.5" tires. I imagine 33's would cram in there but I haven't measured. I'd still want some lift though as on my last trip out I was packing down snow and mud with the skid plate up front while the tires were in deep ruts.

 

[max 02]

I ran 255/85/16 m 55 Toyos, about 33” tall on my old 02 Duramax for years with a half ton torsion keys, about 2” of lift. Oh and shock extender brackets. No other mods needed.
Put 500 thousand kilometres on it set up like that.

 

[max 02]

I've been doing some research into various lift kits for my 2500 'burb. Suffice to say there are a lot of opinions and not a lot of facts that I can easily find. I'm hoping there are a few folks here that can provide some wisdom on lifting a 3/4 ton GMT800, staying with IFS, dealing with the autoride BS, and what (if anything) I actually need to do about the autotrack TCase.

The vehicle is a 2002 suburban 2500, 8/1, LT, AutoRide, AutoTrack, 4.10 gears

The goal is 33" or 35" M/T style tires with 3" to 6" of lift. I'm leaning about 60/40 toward less lift w/ 33's. Can't make up my mind. It must maintain reasonably good highway manners as the wilderness areas I frequent include stretches of 80mph highway to get to. I also plan to tow a popup camper which weighs nothing compared to the tow rating of a 3/4 ton vehicle. No rock crawling. Just snow, mud, and deep rutted out designated trails. I'm not interested in lifting it just to make it taller. I want it to ride better and perform better, knowing that big tires and a lift will degrade the high-speed and towing performance to an extent.

SAS is beyond my skill / comfort level and is basically a $10k job to complete, so it's out of the question unless someone can convince me it's just that damned much better at what I want to do.

I've been looking at the RCD (Race Car Dynamics - the kit ORD sells) and BDS lift kits but i'm open to other suggestions.

• AutoRide: I see many kits mention that they are not compatible with Autoride. I assume the fix is to delete Autoride which i've seen some videos of and it seems pretty easy. Can anyone confirm if that's the only reason and that mechanically everything will fit all the same?
• Autotrack: I've read some folks saying you have to replace the front drive shaft with any lift over some arguable number of inches. What's the deal with that? Should I plan on adding a front drive shaft into my budget for this project?
• CV shafts: Some people have said they break too easily, some lift kits have lowered differentials to correct the angles, some people use longer shafts from later model years. What's the deal? If I lower the diff does it get rid of the problem? Are the shafts just weak, or are people over-stressing them through bad geometry?
• Exhaust: How do I know if I will need to modify something there? RCD says "some models" and BDS says only gas models need it.
• Gears: I've seen people argue either way. I'm tempted to think that with the 8.1 motor I won't have issues running 35's on 4.10 gears. Anyone have experience on that combo?

Here's the burb, because pics are cool...

View attachment 477598

Nice sub!
Nice 60 series too!

 

[Blue85]

Popup is getting a lift too. New frame with a front porch for toys, a 3500lb axle, and some leaf springs. It'll have plenty of clearance.

I've been contemplating something similar.

 

[Stephen]

Definitely run the truck with the 4.10s and whatever tire you want to try first. It's free to try them out and 4.10s and 35's is not a stretch at all with the 8.1L along with the not-super-deep overdrive of the 4L80. We have and have had a number of 6.0L 2500HD GMT800s and have gone to 4.88 with 37s which keep it at about factory gearing and it works well in those trucks so technically you might want to look at 4.56s but given the free 4.10s and the extra big BBC you have, you should try it out for sure.

One of our 2500HDs is on the BDS 4.5" coilover setup. Overall assessment of all of it is that the stock based parts are going to be fine for reasonably hard use with 35s. A narrower tire will help it all out. You'll want all the factory based steering upgrades and will likely be fine running factory shafts. With harder use, a front locker and 37s, I found the limits of the steering but was able to use the stock shafts on some of what I call moderate trails. Not everybody calls stuff like Steel Bender "moderate" as an example.

On shaft strength. I feel like most people can use them reasonably with 35s. I think a lot of the bad rap for CVs on these trucks comes from suspension setup. An example is that we tried a set of cardone HD shafts with the BD kit and found that they bound at full droop before we could get to full steering. How many guys have put all this together and then "blown that sh*& up every time I took it out" but never knew the shafts actually bound up when you steer and droop? Keeping this stuff working right involves a level of care a little above what a solid axle requires. It's not rocket science but it is a step up.

One problem you're going to run into is that you basically get a full cradle lift that gives you 4.5"+, or you do a leveling kit. There really isn't anything in between.

 

[Polymath]

Thanks for the info folks! I'm still undecided but I am leaning towards getting some improved upper control arms and torsion keys with nice shocks from Cognito, and 1-2" rear blocks. Once i've got it lifted i'll measure for clearance on bigger tires. The jump in price and install complexity is just insane from a 3" leveling kit to a full lift kit.

 

[Blue85]

Apparently Duramax trucks have a factory body lift. Maybe 8.1L pickups did, too, but the Sub/XL do not. Maybe those parts are readily available for another inch or so of clearance, without doing a full set of pucks front to back and looking kind of legit.

 

[max 02]

Apparently Duramax trucks have a factory body lift. Maybe 8.1L pickups did, too, but the Sub/XL do not. Maybe those parts are readily available for another inch or so of clearance, without doing a full set of pucks front to back and looking kind of legit.

For the Allison to fit.

 

[Blue85]

Come to think of it, I think Duraburb has some kind of raked body lift they use to put D-max/Allison in, but I don't know if it's factory parts or something else.

 

[imiceman44]

Well there's practically whole forums devoted to what tires on what wheels clear NBS with different lifts, so you should be able to find what you need there. Does that front bumper give you more clearance? I would think the limiting spot is the rear of the front wheel openings and narrow tires with wheels backspaced to tuck in help.

I think 33's can be made to work with almost no lift. My '03 2500 burb is on 31.6" tires now and there's extra room even though I haven't adjusted the torsion bars for the 6.0L-->8.1L swap yet.

Differential drop is always a compromise. The lower you go, the better it is for the CV shafts and the worse it is for the driveshaft. I wouldn't lift more than 2" and use the stock differential location and half shafts. Can't you achieve your goals at 2"? Having wheeled a NBS Yukon XL, I would put priority on removing the running boards and making some kind of skid plate for the giant plastic gas tank. Anything you can do to increase the pathetic stock IFS wheel travel will make your adventures more comfortable, but also increase the complexity of the build. A truck that rides at maxed out height all day to clear the tires would perform better lower with smaller tires.

As for towing, a pop-up is not tough because of the smallish aerodynamic cross-section. But, I question how capable of a vehicle you need for places a pop-up can be dragged.

I made a 35" narrow wheel fit with no lift.
Just had to trim on the inside of fender lip.
I hate lifting trucks.
I prefer making the tire fit and not change the geometry of the suspension

 

[Chris]

I have the same truck, but in white, just levelled it and put on some flares to fit 37's. Works well with 4.10 gears and I did some work on the computer, removed torque limits and changed the tow haul to a sport mode raising shift points etc.

 

[Polymath]

I have the same truck, but in white, just levelled it and put on some flares to fit 37's. Works well with 4.10 gears and I did some work on the computer, removed torque limits and changed the tow haul to a sport mode raising shift points etc.

How in the world does that not cause hell while turning or when it gets rammed up into the wheel well off road? My tires are a tad under 32" and come within a half inch of the rear of the fender well at full lock turn. The bumper I have does not offer much more clearance either.

 

[imiceman44]

How in the world does that not cause hell while turning or when it gets rammed up into the wheel well off road? My tires are a tad under 32" and come within a half inch of the rear of the fender well at full lock turn. The bumper I have does not offer much more clearance either.

I don't know about inner fender, I still have space with 35" tires, it's the fender lip that is almost touching.
He fixed that with cutting the fenders and putting the flares