1968–1970 B-Body, Coronet, Road Runner, Charger Chassis


Your Mopar’s uni-body construction is inherently weak. Our G-Machine Chassis isn’t.

Introducing the FIRST and ONLY bolt-in full frame / chassis for your Mopar unibody!
Thinking about running a 1000hp Hellephant engine? Your stock unibody isn’t going to hold up to that 1000hp monster. Our chassis will, though!

The sheet-metal that your suspension components and engine are mounted to begins to flex dramatically once you add more horsepower, higher spring-rates and better brakes. With our G-Machine Chassis, your engine, rear-end, steering and suspension are isolated from the body. The G-Machine Chassis becomes the main support for your car and the uni-body structure simply becomes added support, helping to tie together the G-Machine Chassis.

The G-Machine Chassis is available for 1968, 1969 & 1970 Mopar B-Bodies:

  • Dodge Charger
  • Dodge Coronet
  • Dodge Super Bee
  • Plymouth Road Runner
  • Plymouth Satellite
  • Plymouth GTX

Installation is simple.

  • The only required cutting is of minor brackets, front frame-rails and front shock towers—creating a “clean” engine bay; As well as a notch in the rear footwell of the factory floorpan. This does not impede the driver’s area at all.
  • The only required welding is of four mounting plates onto the original torsion bar cross-member, and a few reinforcement plates & tube sleeves to the factory rear rails.
  • The only required drilling is of two bolt-holes in each of the rear frame rails

Want wider tires?

  • All G-Machine Chassis allow fitment of up to 345mm-wide rear tires if you minitub the wheel wells
  • The Moser full-floating 9″ is narrowed to 58″ hub-to-hub to allow a deeper dish on the rear wheels

Which options do I choose?


-Our 13″ Wilwood kit is great for daily drivers and the occasional autocrosser or road racer. These require at least a 16″ diameter wheel, though some 15″ fit.
-Step up to the 14-inch Baer 6P Pro-Plus and get a brake system that will suit whatever you want to do. We race our 1965 Tempest often with this brake setup.
-The baddest kit is the Baer 6S, which is a one-piece forged caliper. This brake kit suits the hardcore roadracer, but does not sacrifice street driving.
-The 14″ brakes require a 18″ diameter wheel, however. Additionally, the Baer calipers are available in many colors, while Wilwoods are available only in black.
brake options1

Coilover shocks:

-We use RideTech coilovers as standard on our chassis systems. The two options we offer are single-adjustable and triple-adjustable.
-Single adjustable coilovers offer 24 “clicks” of adjustment for damping, as well as ride height adjustment. These will suit the weekend autocrosser/roadracer, as well as daily drivers.
-Triple adjustable coilovers offer the same damping adjustment as the singles with the addition of high and low speed compression adjustments, and a remote reservoir. These allow you to fine-tune your suspension for a specific type of driving. These are recommended for those who are willing & able to spend time tuning the shocks, and/or for the roadracer where every thousandth of a second counts.
-Air ride is also available, please call for pricing & info.

coilover options1

Rear end housing:

-Our standard axle is a Moser full-floating 9″ style housing, with 31-spline axles. We have tested this rear end up to 1000hp street cars with no issues. Contact us for higher HP, or if you’ll be drag racing it often on slicks with over 800hp.
-The Heidts IRS option is for those craving an IRS in their musclecar. This is recommended for up to 700hp.
-We can also provide Mopar housings for those interested. Please call for information & pricing.

housing options2

Third member/differential:

-The Ford 9″ comes with a clutch-type posi. Our first option is just that, with a cast-iron center section. If you have less than 500hp and won’t be racing the car often, this is just fine for you.
-The Detroit TrueTrac differential is a helical-gear type posi, which holds up to more power than the clutch posi, lasts longer (no wearable parts), and is quiet enough for street cars.
-Moser offers a new nodular iron case which is recommended for 600+ hp and racing. Their aluminum case also holds up to higher horsepower, and is much lighter than iron cases.


(Click to enlarge)

[slickr-flickr tag= “mopar b chassis”]

Base price includes:

  • A fully welded chassis, built on a precision jig
  • Adjustable transmission crossmember
  • All front and rear suspension components (excluding coilovers): control arms, ball joints, tie rods, power rack & pinion, aluminum front wheel hubs with bearings, and teflon-lined heim joints for a quieter & bind-free suspension



We ship assembled chassis using enclosed car transporters. If you order the chassis un-assembled, we’ll ship it via truck-freight in a crate. There is a crating fee, which will be determined upon ordering.
Pricing is for reference only. For questions, call 815.206.2230


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