
The full-size GMC Jimmy shares its body with the Chevy K5 Blazer, and it shares the Blazer’s weak point too: leaf springs and a solid front axle engineered for a 55 mph world. At today’s highway speeds that means wandering steering, a harsh ride and a truck that wears out its driver.
A Frame-Werx chassis keeps the Jimmy looking exactly the way it should and changes how it drives: independent front suspension, sway bars front and rear and a multi-link rear, on a brand-new frame that bolts to the factory body mounts.
Fits
- 1970–1972 GMC Jimmy
- 1973–1991 GMC Jimmy
- The same chassis fits the Chevy K5 Blazer
The Jimmy arrived for 1970, one year after the K5 Blazer.
What it does for a Jimmy
Ride quality
Independent front suspension soaks up broken pavement and expansion joints instead of sending them into the cab.
Handling
Sway bars front and rear keep the truck flat and composed through corners, lane changes and freeway ramps.
Multi-link rear
Locates the rear axle precisely for a settled ride, with the strength to tow.
Rated to 800 horsepower
Engineered to carry modern GM Performance engine and transmission packages.
Two-wheel, four-wheel or all-wheel drive
Build it as two-wheel drive, electronic-shift four-wheel drive or full-time all-wheel drive.
Bolts to the factory body
Built to the original body mounting points. No cutting, no drilling.




Our ’89 Jimmy
Our own black 1989 GMC Jimmy rides on a Frame-Werx chassis. The body came off the original frame and went onto the new one at the factory mounting points. Same Jimmy on the outside, a completely different truck to drive.
Jimmy or Blazer, one chassis
Chevy and GMC built the full-size Jimmy and the K5 Blazer side by side, on the same body and the same mounting points. That means every Frame-Werx Blazer chassis is also a Jimmy chassis. See the 1969–1972 and 1973–1991 pages for the details of each generation.
Spec it your way
Choose shocks from a factory-style setup through Fox, King and Rough Country Vertex reservoir coilovers up front; brakes from a standard aftermarket package to Frame-Werx calipers and Wilwood big-brake kits; a 3.42, 3.73 or 4.10 rear gear; and a GM Performance engine and transmission package. Finish it hot-dip galvanized, or in epoxy primer and black. Buy the bare frame, the frame with parts shipped loose, or a complete rolling chassis assembled in our shop.
Common questions
Does it fit my Jimmy without modification?
Yes. It bolts to the factory body mounts, with no cutting or drilling.
Is a Jimmy chassis different from a K5 Blazer chassis?
No. The full-size Jimmy and the K5 Blazer share the same body and mounting points, so the same chassis fits both.
Which years do you build for?
Every full-size Jimmy, from 1970 through 1991.
Can I buy just the frame?
Yes. It is available as a bare frame, as a frame with parts shipped loose, or as a complete rolling chassis assembled in our shop.
What does it cost?
A bare hot-dip galvanized frame starts at $17,900. Everything beyond that depends on the parts you choose, and the chassis builder keeps a running total as you go.
How do I order?
Spec your chassis in the builder and review the estimate. Frame-Werx chassis are sold exclusively through K5 Squared, and a deposit reserves your place in the build queue.