Build an Autocross Chevy Pickup Like the Carcass OBS Pro Touring 1989 Chevy 1500

Chevy’s 1988-98 OBS (Old Body Style) pickups are getting popular with the autocross and Pro Touring crowd. There are tons of them out there and come with modern amenities like power steering, power brakes, and A/C.

PowerNation TV’s Carcass shop caught the OBS bug and bought a high-mileage 1989 C1500 to transform into an LS-powered cone carver. When the truck was done, they took it to the 2021 C10 Nationals in Nashville, Tennessee and made a decent 32.7 second run on the autocross course.

You can see the Pro Touring OBS build on the PowerNation YouTube channel and see the parts you need to build your own in our Carcass Pro Touring OBS 1989 Chevy 1500 parts list.

Engine Accessories and Exhaust
With over 247,000 miles on the clock, the C1500’s stock 305 cubic inch small block was a tired, wheezy thing putting 175 horsepower to the rear wheels on PowerNation’s chassis dyno. Carcass had their buddies at Engine Power build them a 406 cubic inch LS that made 482 horsepower and 426 pound-feet of torque. You can see the build at PowerNation TV.

After bolting the 406 in the engine bay using a set of ICT Billet swap engine mounts, Carcass built an exhaust system from a pair of Hedman Headers Muscle Swap LS headers, a Summit Racing™ Universal Rod Builder Exhaust Kit with three inch pipes, Patriot Performance electric exhaust cutouts, and a pair of Flowmaster 44 Series mufflers.

The accessory drive system features a Lares power steering pump, ACDelco A/C compressor, and a Summit Racing™ OE Replacement Alternator mounted on the engine using ICT Billet brackets. Supplying fuel to the engine is the job of a FiTech Go in-tank electric fuel pump in an OE replacement fuel tank. The last piece of the engine puzzle is a pair of Perma-Cool 12 inch diameter electric fans pulling a total of 3,200 CFM of air through the radiator.

Drivetrain 
The Chevy arrived at the Carcass shop with a 700R-4 automatic transmission, but inspection revealed it came with a five-speed manual from the factory. Carcass wanted a manual anyway, so they installed a Tremec T-56 six-speed. Our parts list includes the transmission; a Summit Racing™ Manual Transmission Safety Bellhousing to mate the transmission to the 406 LS; a Centerforce Dual-Friction clutch kit; and an American Powertrain Hydramax hydraulic throwout bearing.

Carcass had a Ford 9 inch rear axle built to their specifications. Our parts list includes a Currie Enterprises axle housing with 31-spline axles and a Currie third member with 4.11 gears and a TwinTrac limited slip differential.

Suspension and Brakes
You can’t dodge cones or take sweepers in a C1500 with the stock suspension. Carcass rectified the problem with a coilover suspension setup. Our parts list includes a QA1 Level 3 front coilover conversion kit with double-adjustable shocks and tubular control arms; a pair of Bell Tech two inch drop spindles; a QA1 front sway bar; and Energy Suspension sway bar bushings.

Out back is a three-link designed and built by Carcass. The upper link is a torque limiter similar to the ones used in asphalt oval track cars. When power is applied through the drivetrain, torque will be absorbed through bushings or springs. that helps soften the power hit to the rear tires, providing more forward bite. Carcass also built a cantilevered shock setup using Ridetech HQ Series coilovers. That meant cutting a hole in the bed to clear the shocks, a small price to pay for awesome handling.

The Chevy sits on 18 x 12 Rocket Racing Attack Titanium wheels mounted on 335/30-18 Continental ExtremeContact Sport Tires. Our parts list includes 335/30-18 BFGoodrich g-Force Rival S 1.5 tires. Carcass used JOES Racing and Cal Custom wheel spacers to get the proper wheel and tire fitment.

Stopping power is provided by Wilwood Forged Superlite 6R front brakes with 12 inch rotors and six-piston calipers and Forged Dynalite rear brakes with 12 inch rotors and four-piston calipers.

Paint and Body
Carcass decided on a two-tone paint scheme using Summit Racing™ 2-Stage Cappuccino Metallic paint and a mix of Summit Racing™ 3.5 VOC 2-Stage Gold Rush Metallic Mocha Metallic paints. They sprayed three coats of paint plus two coats of satin Summit Racing™ 2.1 Low VOC Clearcoat.

The bed got a generous coating of Summit Racing™ Premium Urethane Bedliner. Carcass bolted on a shiny chrome Sherman Parts front bumper and grille plus an OE replacement Coast to Coast International front valance. They also replaced the window and door weatherstripping. Our parts list includes weatherstripping kits from Fairchild Industries.

Interior
The Chevy’s cabin had grimy carpet and a beat-up bench seat. Carcass deep-cleaned the dash and panels. They also replaced the rug; our parts list includes Summit Racing™ molded carpet in basic black. The bench seat was replaced with a pair of Procar Sportsman bucket seats that offer much better support and comfort. The factory steering wheel was replaced with a JOES Racing aluminum wheel.

Since the C1500 was built with a manual transmission, it had the brackets for a clutch pedal. Carcass sourced a used factory pedal and bolted it in. A new shifter was bolted to the Tremec T-56 under the transmission tunnel. Our parts list includes a Lokar shifter. A new hole was cut in the tunnel for the shifter to move the shifter back from the factory location.

Parts to Finish
Parts used to finish up the Chevy’s exterior include Dorman door handles, Summit Racing™ replacement taillights , Body Parts side marker lenses, and K-Source OE replacement sideview mirrors. Our parts list also includes Bushwacker fender flares and Auto Ventshade window deflectors.

CHECK OUT THE PARTS LIST FOR THE CARCASS OBS PRO TOURING 1989 CHEVY 1500