1. All general rules apply.
2. Aftermarket one- piece blocks are allowed with a 50.5 cubic in maximum.
3. Must maintain factory head bolt pattern.
4. No external modifications to crankcase.
5. Stock appearing carburetor (1.200 Maximum).
6. Any cam, any valves, any head.
7. Single cylinder, flat head, four stroke must maintain factory deck height. Stock Crank, cam and valve location.
8. Must run on alcohol.
9. Ram tubes allowed.
10. Must have a steel flywheel.
11. .Shielding: 1/8 inch steel ¼ inch aluminum. Shielding will run from the Top of the cylinder to the bottom of the crankcase on both sides. On the front and rear on cross mounted motors. Shields must be bolted to the frame (Stock Blocks Only).
12. Stock Blocks must be strapped with a permanently mounted metal bar.
13. Tires not to exceed 26x12x12.
14. Professional tires allowed.
15. All pro stock drivers must wear helmets and fire suits, zipped and strapped. All pro stock drivers must be able to operate their own tractor and drivers that are 12-15 years old must pass a test before driving a pro stock tractor. (They will be watched by the board members for the first three pulls).
16. No ½ pint style tractors.