3 Inch Custom Spring System 73-87(91) K5, K10, K20, and Suburban with 6 lug axles With Crossover Steering
2 Inch Custom Spring System 73-87(91) K5, K10, K20, and Suburban with 6 lug axles With Crossover Steering
Get the best ride possible while staying on leaf springs!
Great on road ride as well as off road flex!
Check out the FAQ, Instructions, and Product info at the bottom of this page for all the ins and outs of this lift!
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What are the benefits of the Offroad Design Custom Spring System?
Plush on road ride
We take in account all the information on your truck to build you the perfect riding leaf spring possible. This isn't some off the shelf spring built for every truck, this spring is built specifically for your truck. Going from a typical lift spring to our custom springs is a true night and day difference! It is the best possible ride while staying on leaf springs.
Off road flex
With our multi, thin leaf design our spring packs can flex farther without bending. A typical pack is around 10-12" Vertical travel
High quality build
Our springs are made in the USA with USA Steel. We use a military wrap main eye for extra durability. All the springs are dip coated black.
Unlike stock springs or typical lift springs, our custom springs can take a beating and ask for more. They are designed to flex and retain their shape where others go flat
Our springs get all this amazing ride/flex while being able to bolt into the stock locations. No need to go with longer springs
Are the custom springs in stock?
The custom springs are just that, custom so each set is built to order and designed to fit your truck perfectly. The wait is definitely worth it!
What are the HD shackles and Greaseable Kevlar Bushings?
Heavy Duty Front Shackle Kit
Our Heavy Duty Front Shackle kit is just that, Heavy Duty! These are great replacements for the flimsy stock shackles that come with these trucks. We add a .5" to the length of the shackle to help with frame clearance (don't worry we account for the length in the build of the springs). The plates are zinc plated gold for long lasting quality We use better than grade 8 bolts with a high head for the grease zerk The sleeves are made from chromoly tubing To "top" it all off we use a top lock nut
Our Kevlar bushings are a high tensile strength bushing that is built to last! They are also soft enough to not hurt the ride. These bushings are designed with grease channels to help flow to all parts of the spring eye
Bilstein Shock Info
Why use Bilstein shocks
Bilstein is a great all-around shock that is extremely durable. We have selected a valving that is an amazing pair with our custom springs and offers good on and off road ride
Do I need the extended shock mounts?
The stock shock mounts are pretty low on the frame limiting travel of the suspension. This results in lower ride quality and not getting full use of your suspension. Using the extended shock mounts ensures that your suspension will not be limited by the shocks. The extended shock mounts are a benefit for both on and off road vehicles. The extended shock mounts are a bolt on application but do require drilling and cutting. More information on this under product attachments at the bottom of the page.
Measuring Spring Length
Throughout the models there were a couple spring lengths for the rear. The best way to know for sure what you have is to measure your springs. The proper way to measure would be bolt to bolt following the arch of the spring. Do not measure straight across. One way of doing this is using a piece of string to follow the contour and then measuring the spring
What are the xtreme travel shackles?
Our Xtreme travel shackles are a 6” curved shackle that allows for more droop travel and aids in installation of the springs. This extra travel results in a more comfortable ride as well as more performance off road
What banjo bolt do I have?
Our custom spring lift systems come with option of Stainless steel braided brake lines. These lines are DOT approved and pressure tested for leaks. These line will connect directly to your stock hard lines. You will need to select what size banjo bolt fitting you have. As a rule of thumb 1978 and older trucks got 7/16 banjos and 1979 and later got 10mm, to be certain you should measure the threads of your banjo bolt. This can not be determined by what size wrench is on the bolt head. You will need to measure the threads with a caliper like pictured
Why Crossover Steering?
Crossover steering is the best way to correct after you lift your truck. It offers full lock to lock turning throughout the whole suspension travel. the short draglink used in stock push/pull steering it is greatly affected by changes in driving surfaces. This creates an unstable feeling in the steering. With the longer draglink that is used in crossover steering you will have a more precise feel. Street driven trucks and off road vehicles a like benefit greatly from crossover steering. More info on crossover can be found here under our crossover steering page
What is needed for crossover steering?
A 2wd steering gearbox and flat top knuckle are both needed for crossover steering and are available on this page. The 2wd steering gearbox is needed because it is fully splined to accept the crossover steering pitman arm. It will bolt onto your truck just like the factory 4wd one. The flat top knuckle is needed to accept the steering arm on the passenger side. If you have a flat top knuckle on your axle we can machine it for the steering arm, all you have to do is select that option and ship us the knuckle. More info on that can be found here: https://www.offroaddesign.com/labor-to-machine-d44-rh-knuckle.html If you don’t have a flat top knuckle you will need one of the Reid racing knuckles. When selecting the Reid racking knuckle make sure to note the orientation of your tie rod. The castle nut will be either pointing up or pointing down towards the ground.
Can I use my stock sway bar?
No, the stock sway bar can not be used. Luckily we have a sway bar that does work with crossover steering. We also offer it in a disconnectable or non-disconnectable versions.
What is the steering box brace
The frames of these trucks tend to crack behind the steering gear box, especially when more leverage is applied with larger tires. We carry a brace that triangulates that area to help prevent cracks from forming
High clearance pitman arm info
Some trimming of the crossmember may be needed or you can use one of our high clearance engine crossmembers. The high clearance pitman arm is designed to hug the frame as close as possible. Sometimes the end needs to be trimmed down to clear the frame. This can be done with a cuttoff wheel. If you have the steering box frame plate it may require more trimming. Below is a picture of the trimmed end to clear the frame
32s and smaller
No trimming required
Trimming of front and rear of fender opening
37s and larger
Leaf Spring Center Pin Location
For no extra cost we can change the position of the center pin on the custom leaf spring, this changes the location of the axle. On front springs people a lot of times elect to have the center pin moved forward to help with tire clearances. The reasoning for this is as the spring compresses the whole axle moves back with the shackle. With tires larger than 33s this can cause rubbing on the rear fender. Moving the axle forward 1" to 1.5" can help with this, you will need to do drive shaft modifications. Moving the axle forward also helps with approach angles
For no extra cost we can change the position of the center pin on the custom leaf spring. This changes the location of the axle. Moving the axle back can increase your wheelbase and also help with departure angles. If you move the axle back you will need to do drive shaft modifications and body modifications.
Drive Shaft Modification
With our custom springs you will have a lot more travel compared to a typical off the shelf spring, a long slip front drive shaft is usually needed. Typically the rear drive shaft still works but it is worthwhile checking to make sure.
After lifting a vehicle the angle of the drive shaft typically changes. Sometimes the pinion may need to be shimmed to prevent vibration. This cant be checked until after everything has all been installed. We do carry shims to help correct if needed.
What is this kit for?
1973-1987(91) 1/2 ton and 3/4 ton trucks
This kit will work with 1973-1987(91) 1/2 and 3/4 ton squarebody trucks and SUVs. This will not work with the one ton (k30) applications. The applications would be K5 blazer, Jimmy, m1009, K10, K20, v10, v20, v1500, v2500, suburban 1500 and 2500
6 lug axles only
This kit will work with 1973-1987(91) 1/2 and 3/4 ton squarebody trucks and SUVs that have a 6 lug axle either swapped in or from factory. This will not work with any of the 8 lug axles. The axles that do work are the 6 lug corporate 10 bolt and Dana 44 front axle and the corporate 10 and 12 bolt rear axle.
Towing and Hauling
Our springs are designed to give the best ride possible, so they have a low spring rate. To get the best of both worlds (nice ride and towing capacity) we recommend using a set of airbags when towing. There are quite a few kits out there for airbags on these trucks. One thing we highly recommend is the daystar airbag cradles, they allow the airbag to leave/return to the cradle when flexing off road. That way your suspension travel isn’t hindered, we carry them on our website too!
Throwing a few hundred pounds of gear in the back of your truck is not going to be a problem. When you are looking at hauling more than that we recommend using airbags
Below are links to the individual products used in this kit for a more in depth look at them:
|Bolt In Steering Box Brace Instructions||523.4 KB||Download|
|Dana 44 and 10 Bolt Crossover Instructions||358.4 KB||Download|
|Greasable Rear Bushing Instructions||419.9 KB||Download|
|HD Front Shackle Instructions||279.7 KB||Download|
|Extended Front Shock Mount Instructions||204.4 KB||Download|
|U Bolt instructions||178.2 KB||Download|
|Custom Lift System Instructions||155.3 KB||Download|
|Engine Crossmember Instructions||223.1 KB||Download|
|U Bolt Instructions||docx||25.3 KB||Download|
|Sway bar for '73-87 GM truck with crossover steering instructions||905.5 KB||Download|