ExtReme Truck 1967-1972 GM with Torque Arm Rear Suspension


Installation Guide

If you are not familiar with the term Pro Touring consider the following. Trucks from the 60’s and 70’s were manufactured to perform well in a limited range driving circumstances, around the farm and at the construction site. Pro Touring is defined as a classic America muscle car with enhanced capability for braking and cornering. The essence of Pro Touring is a great handling truck that is fun to drive on the street and is also competent on a road-course.


  • Box welded construction with tabbed through frame gusseting for added torsional rigidity
  • Torque arm rear suspension puts loads into the center of the chassis significantly reducing pitch
  • Torque arm controls pinion angle change to a minimal amount, virtually zero
  • Exclusively equipped with forged 7075 Aircraft Aluminum ExtReme spindle (more info below)
  • Up to 27-33 degrees of steering angle equal to or slightly more than O.E.
  • Corrected Ackerman for better grip while cornering providing up to 20% more inside tire grip when cornering
  • Corrected scrub radius for large diameter wheels in wider widths
  • Virtually zero bump steer – .005” standard over full travel (can be tuned)
  • Industry leading design for lower roll center optimized for each chassis
  • Excellent comfort on the street, durable for autocross & track days
  • Increased shock length providing more suspension travel
  • 78% motion ratio for faster shock response and more precise control
  • 3-piece Chromoly tubular splined sway bar standard and a variety of spring rates available
  • Sway bar arms are 3 position adjustable for tuning without changing bar
  • Front and rear ride height adjustments accommodate your vision for styling of the finished truck
  • Trailing arms with Delrin bushings help with binding found in other systems
  • Pinion angle is stable with virtually no change through the rear axle range of motion, acceleration and braking.
  • Rear Roll Center is adjustable over a wide range via the pan hard bar
  • Pinion angle can be adjusted to perfectly set your driveline angle
  • All Speedtech Performance Chassis come with a new Dutchman 9” housing and axles
  • Uses factory body mounts


  • Full Speedtech Performance ExtReme Chassis
  • Custom designed upper and lower control arms
  • JRI mono tube nitrogen charged single adjustable coil over shock, with spring – valved for our ExtReme suspension
  • Adjustable, splined sway bar with options for street, pro-touring/auto cross and ExtReme race
  • Sweet Mfg. dual power rack and pinion steering
  • ExtReme forged spindles with C7 hubs
  • Fully adjustable transmission cross member fits all common Eng. and Trans. combinations
  • Full Torque Arm rear suspension
  • Heavy duty 9” housing and axles with Torque Arm brackets and Pan Hard Bar Bracket welded on
  • 31 spline pro street axles (can be upgraded to 35 spline axles in options)
  • New 9” rear axle housing with 3”x .250” tubes and Big Ford New Style Ends, 2.5” axle offset (full Floater Option available)


  • Included with all ExtReme front suspensions and only available from Speedtech Performance
  • We took the best forged aluminum spindle made and made it better
  • Forged from high quality, light weight 7075 aerospace aluminum
  • Optimized geometry unlike in any other Corvette style spindle in the industry
  • Significantly improved KPI/SAI angle
  • Scrub radius optimized for KPI/SAI changes and larger wheels
  • Requires less caster to achieves optimum tire contact patch
  • Billet steering arm provides increased Ackerman angle
  • Achieves optimum tire slip-angles to provide increased front tire grip
  • Maintains optimum tire grip with less backspaced wheels
  • Brakes caliper bolt pattern is carryover from C5 & C6 Corvette opening up many options
  • Comes standard with maintenance free factory GM C7 Corvette hubs & bearings
  • Excellent design attributes for street cars and race cars
  • Our Spindle provides a more refined and precise driving experience in all situations



  • Frame mounted battery box
  • Coyote, LS, LT, Hemi or Viper Engine and adapter plates
  • Urethane engine and transmission mounts
  • Stainless steel 1 7/8″ headers for most engines
  • Stainless-Steel double joint steering shaft kit
  • Splined adjustable 3 piece rear sway bar
  • Rear end center section with your choice of final drive ratio
  • Aluminum Third Member with your choice of gears
  • Brake packages from Baer or Wilwood with or without E Brake
  • Full Floater 9″ rear axle
  • Ididit tilt steering column*
  • Stainless-Steel Rick’s fuel tank with pump options
  • Wheels and Tires
  • Bespoke PRC Aluminum cross flow radiator with twin Spal fans, shroud, billet overflow, billet rad cap all wiring and relays custom built to fit the ExtReme GM Truck frame

Note: Oil pan compatibility with chassis is specific and the pan will need to fit around the steering rack. Ask your sale person for a recommendation.

Chassis orders will be confirmed over the phone. A sales person will call you for a no cost consultation to discuss the specific details of your project and ensure you are provided with the very best customer experience.

*Factory steering columns have the incorrect length and will not work with the ExtReme suspension components. We recommend an Ididit steering column for best results. Please speak to your salesperson to order from us or to obtain the correct part number.

Note: All chassis orders will have a $900 crating fee plus truck freight shipping added on at the time of processing. These chassis can only be delivered to a shipping terminal or a business with a loading dock and/or forklift access.

Be sure to ask your sales rep about these different options to customize your frame to your needs.