Suburban lift advice

[DJH]

Greetings. I am new to the forum. I own a 1991 3/4 ton suburban currently getting the big "C" from Auto World. I plan to use it on the highway and for some towing but I will also be using it off road quite a bit. I am looking for some advice about a lift. Am thinking of a 6 inch lift and 33 inch tires. Will this kill my mileage/ towing ability? Anyone have experience with a particular brand to use/ not use? (I'm thinking about the additional weight of the cummins etc. )



Thanks,



David.

 

[DVolk]

Suburban lift advise

First of all is it a strait axel or ifs ???



I have a strait axel in my 83 and i put a superlift 8" front 6 "arched springs in the back .



I have a Dana 60 in front . My advise is read your klift very carefully ,see and ask if its tow rated !!!!!!! If its IFS id swap for a strait axel conversion



with a Dana 60 and go with a what ever depending on your t-case your useing ,ford superdutys have leafs springs ,of which will work with a late model t-case ,you might have to convert from full time to part time ,or keep hubs locked in the t-case ,



4 wheel parts advertises 1 ton conversion in there lift kits for strait axel chevy or check out www.jackit.com



My advise go bigger first because it wil lsag with use and abuse



biggest tires i plan is 35"



besure to replace all bushings with poly urthane or heavy duty steel custom if going with a custom spring and make them geaseable



hope this helps

 

[DJH]

Thanks for the reply Donovan,



I do have the straight axle. No IFS so I'm in luck that way. I didn't realize some lifts are not tow rated so I'll ask about that. Out of interest I called my local Les Schwab tire shop and asked them for a price on a 6 inch lift and was quoted around $900. The site you mentioned was considerably higher than that just for the parts so I'll bet Les schwab was not talking all new springs. (blocking instead?) Will I have to worry about changing the Ring/ pinions gears to go up to 33's? What about 35's?



Thanks,



David.

1991 Chev Suburban getting Cummins/ NV4500 from Auto World.

 

[MMcCallie]

Suburban Suspension

First of all, the Cummins is far, far heavier than any engine that GM ever offered from the factory in your Suburban. Yes, most lift kits use higher spring rates as ride height increases, but it may take some trial & error to level the truck. It may also have increased lean side to side.



The best ride for a solid axle is definitely coils. Whether coil over shocks are used or not, the conversion will be expensive. The increased ride quality & suspension travel are very noticeable, but may not be worth the cost & labor.



If you customize your leaf springs, one thing i always do is lengthen them. Unless the truck is strictly a rock crawler, reverse shackles provide a much better ride. I don't remember where the springs are located on your truck, but allot of 4x4s gain a few inches by mounting the spring pack on top of the axles.



Urethane bushings will tighten your suspension & provide better handling. They are stiffer, so they may not ride as smoothly. They are also much more squeaky than rubber.



Shackle & spring hanger lifts will be the least expensive way to get your truck in the air, unless you're looking to improve your current ride quality. 6" sounds like more than you need for 33" tires. I prefer to trim fenders before lifting a vehicle unless it is required for the trails.



Ask around for what lifts people like best. You may be able to get away with simple add a leafs for a little more height & compensation for the weight of the Cummins. Body lifts are also a cheap lift alternative & may even make your Cummins swap easier by making more clearance for the drivetrain.

 

[DVolk]

I agree with the other reply to a point ,but not fully , here is why



Im guessing if your like me your building a burb so you can haul the family and tow a hell of alot of weight , of which a reverse shackel will not give you and its not cost effective to put coils on a daily driver and occasional trip into the woods for hunting or camping , if you put as i sugested greasable bushing and pre grease them you wont get sqeaky from the springs i did this on my old power waggon i beat the hell outof pro arena raceing and it dont squeak . you have to lift the burbs for oil pan clearence 4" for a dana 44 and 6" for a 60 and it will sag about 2" even with a gas engine in it .

Ive been lifting and raceing 4x4s for 20 years ,when i was young and dumb

i put lifts on in a foot of snow



one thing to renember and the reason i didnt go with les schwab ,i have in the past they only sell rugged trail lifts of which is 4 leafs you need at least5

to hold that cummins look at any gen 1 truck they got a lot of leafs in front

Ive seen a couple of trucks with basicly stock springs and they were doing upside down Us if you can vision that stay awayblocks

i did use and do recomend the front shackels from www.offroaddesign.com

i might use the rear shackel too

 

[24VChev]

I have done a few of these conversion to the Chev's, I have weight the front end before and after a Cummins conversion from 454 and 6. 5's. When you install the Cummins in the truck the engine, transmission and t-case are moved about 3" to the rear. The increase on the front end is only about 150 lbs with the cummins installed



I would go with a BDS 6" suspension and all new springs in every corner. You Might have to go with ProComp for the rear spring because BDS might not make rear springs.



If your truck has 3:73 gears now you will be good to go with 35's espcially if you bomb the cummins.



Good luck



Malcolm



PS 500HP twin turbo 1994 chev for sale.....

 

[DJH]

thanks for all the replies. I'm picking it up late this month can't wait...



I think I'll go with the 6 inch spring lift even though I might not put bigger than 33's on it for now. Sounds like blockes are a bad idea. I had a 1969 FJ-40 Lancruiser that I lifted. The guys told me the lift would accomodate 33 inch tires no problem, but when I installed it, the tires rubbed all over the place when I even started to tweak the rig on the trail. I don't want to go with an undersized lift with the sub.



BDS? Not sure I've heard of them. Where do I price BDS?



Thanks again everyone,



David.

1991 Chev Suburban getting Cummins/ NV4500 from Auto World.

 

[DJH]

Oh, forgot to comment, Donovan, about doing the lift in a foot of snow. That's funny... It has been so hot this summer, I must admit that doesn't sound quite so foolish now though!!



David.

1991 Chev Suburban getting Cummins/ NV4500 from Auto World.

 

[DVolk]

Suburban lift advise

Yep it is kind of foollish to do a lift in the snow ,but heck i was 19 0r 20 and wantd to go raceing so i did what needed to be done ,now its hot in the shop and i got cealing fan going to keep a breeze moveing



I for got to commit on the gearing you will be fine to run 33's or 35's with gearing thats stock 4:11s will be better rpms at hi way speeds

 

[DVolk]

Suburban lift advise

How much is your conversion costing you ? mine is will be $7000. 00 when done no labor cost envolved yet

 

[CumminsChick]

I have a 88 Suburban that's getting a 6inch superlift springs all around, with 35s... and mine will be highway and OHV use. i'm also adding dana 60 front, corporate rear to the mix to strengthen the weak 10bolt in her now.



DVolk-my lift is costing a lil less than what your paying w/o labor (i'm doing mosta it) them axles are expensive but a must!

 

[SOswalt]

What ever you do don't get the soft ride front spring they will sag a lot.



I also think depends on what engine mounts use (mine that I sell) move the engine forward not back so there will be more weight on the front axle.



I used super lift 8'' springs HD and they still sag about a 1'' or so,But I have a Crewcab and all lift manufactures say even though the lift will work they were made to hold the weight of a crewcab.



Rear blocks will work as long as you don't go to tall and don't do extreme wheeling. Yes rear spring are better than blocks.

 

[DVolk]

Suburban lift advise

my lift and axels was not $ 7000. 00 thats total parts for the conversion



Cummins Chick definately buy Scott Oswalts mounts they work i know because i have them ,thanks Scott !!!!!!!!!!!!!!!!!!



i got a questions for you and pics if i have not already sent them to you

Donovan

 

[DJH]

Don't know exactly the bill yet for the conversion, but It'll definitely be more than twice what you have estimated for yours!!!



David.

 

[CumminsChick]

i paid a lil more for my axles than i wanted to but in the end its all worth it. if you are gonna do it, than you better do it right... or that's how i was raised



when i am ready to drop the engine in i will def be looking for them mounts. i'm in college and scrounging money for the project as i can get it. waiting righ tnow for transmission money... work work work!



any questoins just email me or ask me. i will take any advice and help i can get also... thanks' ya'll for the help! this place is great! (tdr)

 

[DKarvwnaris]

Don't know exactly the bill yet for the conversion, but It'll definitely be more than twice what you have estimated for yours!!!



David.

If you already have Kenny (autoworld) doing the repower for you, why don't you just have them take care of the lift as well?... They can get just about any brand you want to put under it. he knows what works and doesn't. A big block suburban with a snow plow is heavier than the 5. 9 conversion. Make sure you have the technical support call center of whatever suspension company you choose verify they have a sufficiently rated option for you. ANy spring you put under the vehicle is going to sag, that's what leaf springs do, some less than others.

I've had bad luck with Pro Comp, Sky Jacker, and Trail Master. The only ones I didn't have to replace at least twice was Rancho and National Spring. Its been a few years since I've had a lifted straight axle so keep that in mind, quality may have gone up or down with different namebrands.



On a side note, 1991 only offered the RV model suburban and crew cabs. 1992 was the change date for these models. IFS was only available in the 1/2 ton and light 3/4 pickups before then. 1988 was the first year of the IFS model 1/2 ton pickups)

 

[Dwey]

Hi there DJH, I have a 1981 one ton four wheel drive chevy(same stright axel set up), with the 60 series frount axel and 4:11 gearing. It has a 4 inch supperlift suspension kit in it for about 4 years now,and I run 33 by 12 wide tires with lots of clearance. I run my truck in the bush at least 50% of the time(fire wood),and pull a equipment float at least 60% of the time, and plow snow all winter. The front springs at that time were the heaviest I could buy(in a lift kit),I have rubber suspension blocks under the springs in the winter for the plow,then remove them for summer,and use polyurhane bushing through out. I run a fresh 6. 2 diesel, but I will be hopefully converting to a 6B some day. The 6. 2 weights 701 lbs and the 6B weights 880 lbs,I should be able to add one more heavy leaf spring,from 5 leafs now to 6 leafs (like the factory dodge truck has),with out to much problem. As for the back springs, this one ton has factory 9 leaf springs(new cond. . ),with taperd lift blocks,I can haul and pull very heavy loads(with org. . 454)with no problem at all. Best thing I ever did was the lift kit,the worst was the 6. 2(not enough power). Anyways the suburban with its extra weight would handle this perfect,with out to much towing issues,(have a proper hitch with torsion bar set up)DWEY.