By Jon Asher
SPECTATORS AT SOME OF THE NHRA national events got a special treat last year when Don Stringfellow’s colorful GMC Sonoma pickup pulled to the starting line to make demonstration runs. Of course, after the mind-boggling performances of the likes of Amato and Force, it’s unlikely that a 9-second. 133-mile-per-hour pickup is going to make the fans turn handsprings—until they realize that powering this little monster is just 302 cubic inches of V6!
At 130 mph, Stringfellow’s quarter-mile blasts are some 70 mph slower than his other truck, an almost mirror-image GMC that this Heher Springs, Arkansas, racer drove to a 204.70-mph international record at the Bonneville Salt Flats in 1990. Because he is obviously no stranger to high-speed driving, GMC asked Stringfellow to help them come up with a quarter-mile version to demonstrate what they could do on a “short track,” and he was happy to oblige.
The centerpiece of the GMC Truck Motorsports display at the NHRA national events last year, Stringfellow reports that the fans showed considerable interest in the truck, as they realized that this machine combines very competitive quarter-mile performances with a relatively minor financial investment. Obviously, this is no bargain- basement ride, yet it’s far from the costs of some of today’s pricier Super Gassers (the bracket this machine most readily fits into).
The chassis was assembled by Vehicle Research and Development of Almont, Michigan, utilizing componentry from Alston, Strange Engineering, and Chassis Engineering of Jupiter. Florida. The team at VRD began with an Alston kit, but as you might imagine, since the demand for quarter-mile chassis kits for GMC Sonoma pickups isn’t that high, they had to modify the rollcage area, as the cab of the truck is considerably smaller than the greenhouse of a full-sized car. Everything from the wheel tubs to the interior paneling came from Alston.
The Ford (Pssssst! Don’t tell the GMC Truck guys this!) 9-inch rear-end was narrowed and outfitted with Strange Engineering internals and a set of 5.42:1 gears bolted to the spool. JFZ disc brakes are incorporated, while the actual suspension is a coil-over system from Chassis Engineering. Up front there’s a Strange A-arm arrangement with Strange struts and another set of disc brake.’1’he stunning wheels came from Hot Rods by Boyd’s. while the rolling stock is from Firestone.
For consistency’s sake, GM Powertrain/ Hydramatic Motorsports of Ypsilanti. Michigan, built the 3L80 (THM 400) automatic trans using a high-stall-speed converter, a trans cooler, and a Hurst Quarter Stick shifter. And while the automatic trans isn’t a surprise, the powerful Katech-built V6 engine underneath that lift-off fiberglass hood is definitely unexpected. Based oil the 90-degree GM powerplant, this monster displaces 302 cubic inches of dependable 9-second elapsed time power. The special Vortec V6 utilizes a Moldex crank, Clevite bearings. and a combination of, Carrillo rods and Cosworth pistons to produce it whopping compression ratio of 14.3: 1 . The valvetrain consists of a General Kinetics camshaft, Iskv lifters. Diamond pushrods, Ryan Falconer rocker arms, Competition Cams springs, and Del West titanium valves. Lubrication for this production 4.3-liter-based engine comes from Mobil 1 and is circulated by a Weaver Brothers dry-sump system trough a Katech oil pan. The braided steel lines for the oil, water, and fuel all came from Earl’s Supply. The ignition system includes pieces from Delco, with the spark plugs corning from AC Rochester. The plug wires are Moroso products, while the gaskets are a combination of Fel-Pro and General Motors products. The valve covers are off-the-shelf GM items, while the headers were custom fabricated by Katech Incorporated, in Mt. Clemens. Michigan.
One of the truck’s most interesting aspects is its induction system, which consists of a Kinsler fuel-injection unit and a Delco engine management system to ensure that fuel delivers is consistent with engine demands. Ironically, while this kind of system might seem just a bit out of the ordinary for a racing vehicle, the reality is that today’s OEM fuel-injection systems are even more sophisticated than the Kinsler unit. While Don and his wife Barbara handle everything by themselves when their GMC Truck Motorsports rig is on the road, they were joined for our photo session by Eric Dahlquist from The Vista Group, Super Gas racer Ken Robinson, and John Van Heusden from Vehicle Research and Development. Despite the recent cutbacks in GM operations. Stringfellow reports that the GMC Truck Motorsports travelling display will once again make most of the NHRA national events, where his colorful Syclone LSR Drag Truck will make exhibition runs. With its wheels-up launches and impressive elapsed times and speeds, this is definitely one hot truck.