4" lift recipe, opinions wanted

[pma4x4]

Ok, so we just got a 1991 Suburban 1500. I have already searched the forum and found some close answers but nothing definitive. I thought I would post this up as a whole and see what i find.

We are building the Suburban for expedition off-roading. This means it will see a lot of asphalt so ride quality is a priority. This will not be crawling rocks or doing WOT thru the mud. It will how ever be carrying a load. Below are the specs and the recipe of our lift. I am open to all opinions.


Specs:
1991 burby
5.7 TBI new GM motor 45k ago
700R4 with 30k GVW cooler
10 bolts front and rear geared to 4.10 Limited in rear. Rear will be trussed
33x10.50x15 BFG ATs Load range C
DYI4x Abomb winch bumper center WITHOUT the B52 mounts
Warn M8000 (yes I could use bigger but i had this laying around)


Recipe
Frontend
4" TC HD springs (stock length)
New ubolts
Bilstein 5125 valving 255/70 (there are other valving options I can go 298/94)
ORD shackle kit
All bushing greasable
FUSH kit from ORD


Rearend
Shackle flip kit from ORD or DYI4x (have not made mind up yet)
4.5 shackle from ORD or DYI4x (have not made mind up yet)
Ubolt reversal kit from ORD
Bilstein 5125 valving 255/70 (there are other valving options I can go 175/60)
All bushing greasable


STEERING
frame brace from ORD
Weld in frame plates from ORD
4" drop pitman arm (I do plan to swap out to crossover down the road)


I plan to add a bit more bumper material to the front but only in 1/8" wall type stuff.



The questions is am I going too heavy on the front springs? should i go with the EZ rides or stay HD. What do you think on the shock valving?

 

[munepit]

The EZ Rides with the bumper and winch might make the front lower than the back and might be too soft. Call ORD and have custom springs made. They would be built just for your rig. Not much more than the ones you have listed and would be a much better riding spring.

 

[1BEATK5]

Get the raised steering arm. Not a drop pitman. I don't think they make a 4" drop pitman arm anyways.

You Dont need the u- bolt flip either. Yours are already facing up.

I would go H.D. or custom front springs also with the winch and bumper.

 

[pma4x4]

Sorry wrong nomenclature

4" Raised steering arm

Thanks on the ubolt info.

As for springs I think I will be going with the TC HD 4"

 

[jms]

I've had Bilstein 5125 w/ the 255/70 valving on my K5.
I didn't like them at all, way too soft to control my front D60.

What worked out well for a while was to have a front quad shock setup with those 5125s, where all of them were the 255/70 variety. They're off my truck now, as a seal let go on one of them...

I've since switched to a Bilstein 5100 originally intended for a Ford Superduty, and that seems to work out well, both in terms of ride quality, and trail performance.

 

[pma4x4]

I will look further into shock valving. As for my front end I only have a 10 bolt. I am trying to find a 3/4 ton D44.

In the 5125s I can go to 298/94.

Jims, what all do you have on your front end what size of motor etc?

 

[colbystephens]

I will look further into shock valving. As for my front end I only have a 10 bolt. I am trying to find a 3/4 ton D44.

In the 5125s I can go to 298/94.

Jims, what all do you have on your front end what size of motor etc?

If you're staying with the 10 bolt rear end, why bother with the 3/4 ton front? And why a Dana 44?

For what it's worth, I have Bilstein 5100 shocks on all 4 corners of my truck, and I like them a lot. I have a D60 front and 14BFF rear.

 

[pma4x4]

If you're staying with the 10 bolt rear end, why bother with the 3/4 ton front? And why a Dana 44?

For what it's worth, I have Bilstein 5100 shocks on all 4 corners of my truck, and I like them a lot. I have a D60 front and 14BFF rear.

Sorry I made it confusing.

I am on the hunt for 3/4 ton axles front and rear. I currently have 10bolts front and rear but I want to upgrade trying to find 4.10s with a stronger axle for carrying capacity.

 

[jms]

jms, what all do you have on your front end what size of motor etc?

Above the springs: 350, second battery, ORD front bumper, Ramsey REP 9.5e winch. 3" TC HD springs; below: D60 w/ x-over; 35" MTR Kevlars on steelies. So, unsprung weight probably 750lbs?

...
For what it's worth, I have Bilstein 5100 shocks on all 4 corners of my truck, and I like them a lot...

5100s are different compared to the 5125s.

 

[pma4x4]

So maybe instead fo trying to guess what valving i need with 5125s just get the 5100s as per Bilsteins recommendations?

 

[K85 Octane]

Nah, just ask for that specific valving they offer when you order the 5125s. Also, you are going to want a 3/4ton rear leaf pack at the least. Or, have some leaves made. But you are only 1/2 ton rear, and using the shackle flip means using the stock 56s.

Really, I would just explain what you are looking to do with the truck to someone at ORD, Stephen or Chris, and order an all leaf lift. Nevermind the shackle flip, just get a nice set of springs for each corner.

 

[jms]

Nah, just ask for that specific valving they offer when you order the 5125s...

5125s are not application-specific. 5100s are...

My 5125s rode nice on the street. On the trail - well, I actually changed them out for ProComp ES3000 for a while. The front quad 255/70 setup worked well, though, but that was spur-of-the-moment...
One other little tidbit: Bilstein shocks are not warrantied for offroad use...

 

[pma4x4]

5125s are not application-specific. 5100s are...

My 5125s rode nice on the street. On the trail - well, I actually changed them out for ProComp ES3000 for a while. The front quad 255/70 setup worked well, though, but that was spur-of-the-moment...
One other little tidbit: Bilstein shocks are not warrantied for offroad use...

Never heard that on the bilsteins. Funny thing is OMEs are repainted and labeled Bilsteins and they are warrantied for offroad. Frankly if OME made shocks tall enough for 4" lifted fullsizes I would go with them.

 

[pma4x4]

Nah, just ask for that specific valving they offer when you order the 5125s. Also, you are going to want a 3/4ton rear leaf pack at the least. Or, have some leaves made. But you are only 1/2 ton rear, and using the shackle flip means using the stock 56s.

Really, I would just explain what you are looking to do with the truck to someone at ORD, Stephen or Chris, and order an all leaf lift. Nevermind the shackle flip, just get a nice set of springs for each corner.

I am actually in process of trying to acquire an entire 90 3/4ton burby. so that would give me the springs. plus a spare 350 and 700r4 to tinker with.

The idea with the shackle reversal is to gain the 4" i want but maintain a flatter spring for better ride.

 

[Stomis]

Do a 52in front spring swap if ride quality is an issue. Ditch the sway bar, do crossover now its important on and off road. Dont waste money on push pull steering. Run some stiffer shocks to control the sway, or even duals, or put an antirock bar in the thing.

 

[pma4x4]

Doing a 52 swap was the original plan until i heard that it moves your axle forward which creates other issue. different drive shaft, fender trimming. steering components upgrades mandatory. I only have so much free cash for this project and gears and at least one ARB is mandatory and thats only after i figure my axle situation out.

I am still (re)new in FS chevy, have been out of it for a couple decades so I need to relearn all this stuff.

Also remember I am not wheeling this thing hard at all this is a purpose built expedition rig.

 

[colbystephens]

5125s are not application-specific. 5100s are...

Sort of... The 5100s can be purchased application specific, but I just looked up their list of shocks and bought the ones that were the length I wanted.

 

[Blue85]

The 52" front spring swap can end up locating the axle wherever you want it. It's just that the cheapest way moves it a couple of inches. You can always get brackets from DIY4x. I would avoid 3/4-ton springs if ride quality is really important. Same for Tuff-Country HD (although you can pull a leaf later and make them into the non-HD version). Call ORD and ask about the custom springs. Way way softer and can set you at whatever height and whatever axle position you want.

 

[blazinzuk]

So some have a different view of expedition wheeling than I do, I want to go where not many other folks have been. I can explore forest service roads that are maintained in just about anything. So while you may not expect it to be crawling through rocks or blasting through the mud, that may in fact occur occasionally.

Now onto the lift. You want a total of 4" correct?

So off the shelf stuff I would do a 4" shackle flip in the back. Simple.

Front is different, 2.5" lift springs. New upper shackle hanger (which I would relocate but thats a whole nother discussion) , longer shackles, an ez inch ( diy4xs version of the zero rate). Run the EZ inch so that it moves your axle forward an inch, which should allow 35s with very very mild trimming. That would bring your total to 4".

Look into custom springs. When you add up all the costs they don't come out too much more and are way better. Yes they are more, but they can give you a better overall ride than any off the shelf spring.

Now onto steering. IMHO since your going to be driving this long distances I think steering should be pretty high on your list. The xover steering isn't just for hardcore guys, it makes the steering so much better overall. I plan on doing it to even my future tow rig, which will only be lifted a couple inches and rarely go off road. It just makes em drive nicer overall.

As far as shocks go if you are going to spend the money on Bilstiens its not to far to wait and get a set of rebuildable kings or Fox shocks. It will take some doing to get em tuned in, rebuilding them is not hard at all and can really dial in your ride.

 

[pma4x4]

This is some really good input guys, I do appreciate it very much.

The crossover steering will happen, just not on this initial build. As far as springs go I would prefer to stay with something "off the shelf". I understand that does have some limitations but I am trying to keep with "common" parts for lack of a better word for replacement reasons.