The 1988–1998 GMT400 K1500 (4WD) is a popular platform for mild to moderate lifting. A 4-inch lift opens up room for 33–35" tires and gives the old OBS truck a commanding presence. Here’s how to do it right.
GMT400 Front Suspension:
The K1500 (4WD) GMT400 uses a solid front axle (Dana 44 or Dana 60) with torsion bars. This is different from the 2WD which uses coil springs. The torsion bar system is easy to lift.
Torsion Bar Crank (Free Lift!):
Before buying any parts, crank your torsion bars. The OEM torsion bar adjuster bolts under the cab can be tightened to raise the front 1.5–2" for free. This is step one for any lift.
4-Inch Lift Components for K1500:
To achieve a full 4" lift:
- Crank torsion bars (1.5–2")
- Add torsion bar keys or extended drop brackets (1–1.5" more)
- Rear: 4" lift blocks or replace leaf springs
TORCH 3" Front + 3" Rear Lift Kit for 1988–1998 K1500 4WD – Provides the lift blocks, U-bolts, and hardware for the rear while the front is handled via torsion bar adjustment.
Tire Fitment with 4" Lift:
- 33" tires: Fit without rubbing on most builds
- 35" tires: May require minor trimming at full lock
- 37" tires: Require full fender mods
Caster Correction After Lift:
Lifting the front of a torsion-bar truck changes caster angle. Use caster correction shims or aftermarket upper control arms to restore proper geometry and prevent tire wear.
Shocks:
After lifting, you need shocks with more travel. Bilstein 5100 or Fox Performance shocks work great on lifted K1500s.
What’s your lift setup on your GMT400? Share tire size and any rubbing issues below!