Class Spokesman

Lanny Highbaugh (270) 268-8986


Randy Simmons (270) 646-8692

1. Vehicle must have a cable operated engine air intake shut off device. Device cannot be butterfly type and must be spring loaded. Cable must be located approximately 4 feet above the point of hook and within 6 inches of center of vehicle. Device must prevent the engine from building boost. The sled requires a 2” ring or equivalent be attached at the end of the cable. Mount cable in clear view with no obstructions. One must be within driver’s reach as well when strapped in seat.

2. All tractors must have working rear brakes capable of sliding each rear wheel.

3. All tractors must have a steel or an SFI approved flywheel and an approved blanket.

4. 470 Cubic inch maximum. There will be a 1% tolerance on all engine measurements.

5. All cooling fans will be electric operated. No factory metal blades on water pump.

6. Maximum of 114” wheelbase unless originally produced with a longer wheelbase, at which point the wheelbase will remain stock. Maximum length of 13’ from center of rear axle to forward most point of the tractor, excluding front hitch.

7. A 3-way fuel dump bypass valve is required ahead of the injection pump. This valve is to be operated by a cable within the driver’s reach when strapped in the seat.

8. Drawbar must be a minimum of 18” behind the center of the rear axle, a maximum of 20” in height, and be ridged in all directions. Hitching eye is to be a minimum of 1” thick and a maximum of 2” thick with a 3”X3.75” inside diameter hole. All hitches must pass tech inspection for safety.

9. Engine must be OEM stock block, head, intake manifold and exhaust manifold must be for make and model of vehicle being entered. No aftermarket components allowed.

10. Vehicle must be equipped with a minimum of a 2.5 lb dry type or a 2 lb halon type fire extinguisher that must be located within easy driver’s reach. Must be fully charged and have a working gauge.

11. All tractors will have fenders and must support the weight of the driver. The top of the fender must extend no less than 6” over the top of the tires.

12. All tractors must be equipped with a floorboard that is at least 0.060” thick and must be steel or aluminum.

13. Fuel Pumps Allowed: Rotary, A Pump (no larger than 14mm for the A Pump), P Pump of 13 mm plungers (for P Pump only) or smaller (P3000 or P7100; no P8600) Only one plunger per cylinder. Throttle stop must be on the pump.

14. Diesel fuel only. No compressed gases of any kind allowed as additive. Must pass Styrofoam cup test. Random fuel checks can be completed by a 4-minute cup test or dialect test with a maximum reading of 5.

15. Vehicles MUST NOT start in gear.

16. Driver must wear a helmet, complete fire suit, neck collar, and leather shoes.

17. All tractors will be equipped with an approved roll cage.

18. 3000 RPM maximum, with 100 rpm tolerance. Must have magnetic tape on balancer or on flywheel. Also, vehicle must have an ISPRO #019R8906 magnetic pickup attached to the front of the engine to measure engine’s RPMs. The lead from the pickup to the rear of the vehicle is to be made of 14-16-gauge wire extension cord with a molded 110V, 3 prong female electrical outlet. This 110V plug needs to be mounted next to the rear mounted air shutoff able. Wire must be one (1) continuous wire outside the frame rails and visible. NO SPLICES! Each tractor will get one no read per season on RPM box. The second time, the tractor will be disqualified. When RPM box does not read, the tractor will be checked by hand tach for that one no read. When RPM box unavailable, RPM’s will be checked at scales by RPM gun. 

19. Each tractor is to look standard for its year, make and model in appearance. All major factory sheet metal is required.

20. Stabilizer bars are required (no wheels allowed). The stabilizer bars cannot be welded or bolted to the hitch in any way. The stabilizer bar must extend a minimum of 32” rearward from the center of the rear axle. The skid pad cannot be more than 10” off the ground. The skid pad must be a minimum of 5” X 5” square. A minimum of 20” is allowed between the 2 skid pads. No cross bars are allowed on the stabilizer bars behind the hook point. In addition to the stabilizer bars, the vehicle must have a brace that extends vertically 12” from the rear most tip of skid pads. There must be a support brace extending inward to frame, axle or top of stabilizer bars. Design and material used must withstand impact of sled and support the weight of the tractor. Vertical brace should extend rearward a minimum of 2” from radius of rear tire.

21. A 5-point harness is required.

22. Side shields are mandatory on both sides of the engine and must cover the entire engine. They are to be either aluminum or steel and not less than 0.060” thick. There must be a firewall that separates the operator from the engine compartment with no hole more than ½” in diameter for controls to pass through. A 0.060” thick or 0.120” aluminum piece must run between frame and under the harmonic balancer to prevent the loss of the harmonic balancer from the tractor.

23. Tie bars are mandatory on all tractors.

24. 20.8 X 38 tires. Cut tires are allowed.

25. Throttle lever must have a double spring installed such that, if the throttle lever is released, the engine will return to idle. Throttle must function such that moving the throttle lever forward increases the engine speed.

26. Aftermarket frame and front ends are allowed and must support the weight of the tractor. Ski bars are mandatory on all tractors.

27. Turbo will be a single turbo with 3” maximum diameter of the intake inlet. Bushings may be used, but must be permanent. Compressor wheel must enter into the compressor housing. 0.200 map width enhancement grooves allowed. NO restriction on exhaust wheel size. Measurement of the inlet will be done by using 3.000 plug or internal calipers and measured at the front face of the wheel. Two 3/8” bolts in a cross pattern must be welded in the exhaust pipe, no curve exhaust allowed.

28. Water injection is allowed with water and pump lubrication only. Water may contain crop oil or water-soluble oil. Water must freeze rock solid.

29. NO INTERCOOLERS, AFTERCOOLERS, OR ICE BOXES of any shape or form allowed in the air intake system of any tractor.

30. Must be steel weld on hubs or heavy-duty clamp on hubs. No cast iron.

31. The protest for engine measurements will be $500. 

32. 1st place tractor at each event will undergo a fuel check. In addition, random fuel checks will be conducted as chosen by tech officials. On nights selected for a random check, all participants in the class that night will be checked. Fuel to be tested will always be extracted from the dump valve.


          1. Membership must be paid for voting rights at annual class meeting.

          2. Class will not earn points.

          3. Payout for this class: $900: $400, $300, $200