1. Maximum cubic inch limit is 540.

2. No overhead cams.

3. A recast head for the series of engine used is permitted.

4. No component rear ends are permitted.

5. No aluminum heads are permitted.

6. Any exhaust manifold is permitted.

7. Only fuel permitted is diesel fuel.

8. Pressurized containers for fuel are not permitted.

9. Tractors are allowed a single (1) turbocharger with any manifold modifications necessary to mount the turbocharger. Manifold pressure may be a single (1) stage only.

10. Legality of the injector pump by officials is based on the visual inspection of the outside housing and not the inner workings of the injection pump.

11. ‘A’ PUMP: Only one (1) plunger per cylinder and one (1) injector per cylinder is permitted. No size restriction on Turbo. Also limited to 4.5 inch outlet ID. Weight is 8,700 pounds.

12. No Sigma or MW pumps are permitted. (’A’ and ’P’ pumps only)

13. ‘P’ PUMP - (SEE ABOVE) 540 cubic inch maximum - WEIGHT 9,300 lbs. The turbocharger compressor turbine and exhaust wheels must protrude at least 1/8 of an inch into the compressor inlet and exhaust housings. Turbocharger intake may NOT exceed three (3) inches and exhaust may NOT be larger than four (4) inches. The 3.00 inch inlet limit will be measured at the face of the wheel and the 4.00 inch exhaust limit will be measured at the face of the wheel. Reducer rings are permitted and MUST be permanently welded in place (with a minimum of four (4) permanent welds) with absolutely NO othersources of airflow are permitted either at the intake or exhaust side. ANY additional holes, ports, rings or grooves will be considered as ‘additional’ sources or airflow and will deem the tractor illegal.

14. Limited Pro Stock G-Trim Max on Exhaust side of turbo. Maximum 4.5” outlet I.D.


Maximum tire size is 24.5 Double cut tires are permitted. No radial tires are permitted.


  1. Drivers safety uniform shall be the same as Pro Stock Tractor requirements

  2. Approved blanket or blow proof bell housing required. Blanket must be of sufficient size and length to completely cover the ‘rear most part’ of the bell housing.

  3. Clutch must be a high performance type. ABSOLUTEY NO CAST IRON COMPONENTS ALLOWED.

  4. All tractors must have 47.1 SFI Spec rollover protection.

  5. A five (5) point harness is required (see Pro Stock Tractor rules).

  6. Approved kill switch is required (see Pro Stock Tractor rules)

  7. Wheelie bars must support the weight of the tractor.

  8. All tractors must have side shields (see Pro Stock Tractor rules).

  9. All tractors must have fenders (see Pro Stock Tractor rules).

  10. A second safety hitch is required on all tractors (see Pro Stock Tractor rules). Hitch will be measured while on the scales.

  11. Sampling fuel on diesel engine: All diesel powered competition vehicles will have a fuel sampling valve (closest to injection pump) on the return line from the fuel injection pump to be used in obtaining a fuel sample. The sampling valve needs to have a flexible hose. Diesel engine needs to be running when the fuel sample is obtained. For 2022 Diesel fuel test will be minimum low of 30 to high of 150

  12. All diesel powered competition vehicles will have a water injection sampling valve. If no valve exists, the tank line will be unfastened to attain a sample.

  13. All fluids are subject to diagnostic screening.