2025 6,200 Pro Stock 4x4 Rules

1. Maximum weight is 6,200.  
2. Engine 485 maximum cubic inch limit.
3. Engine must be 14 inches from back to center of axle.
4. May run cast iron heads or aluminum heads retaining OEM bolt pattern. No Hemi or Big Chief type allowed. No A460 Ford Heads allowed.
5. No tunnel ram or sheet metal intakes. Small block or less are allowed any cylinder head. 
6. No fuel lines of any kind may be routed through the cab, unless factory equipped.
7. No forced air-induction, super chargers or turbo's allowed.
8. If equipped with a fuel cell, it must be mounted in the bed or on weight rack from the grill forward.
9. Limited to 1 carburetor or stock fuel injection.
10. Any transfer case allowed.
11. Any transmission allowed.
12. Front axle may be any size.
13. Any rear axle allowed.
14. Maximum wheel base 133 inches with a 1/2 inch tolerance.
15. Weights and weight bracket must not extend forward more than sixty inches from the center line of front axle.
16. The hitch will be the furthest point to the rear (except for safety bumpers).
17. Maximum hitch height is 26 inches.
18. Hitch must be solid in all directions and secures no more than 6 inches from hook point.
19. Maximum hitch length: 36% of vehicle wheelbase (133 inches wheelbase x 36% = 47.88 inches from rear axle center line to hook pt).
20. No clevis, chain or cable allowed.
21. Tire size must not exceed 33 inches outside by 12.5 inches to outside of tread.
22. Body must be of factory appearance.
23. Body must have full cab and firewall.
24. Dash may be removed.
25. Bed floor may be removed but must install bed cover.
26. Wheel base must remain factory wheel base (with a 1/2 inch tolerance).
27. Vertical headers allowed (alcohol trucks vertical required).
28. Drive line brakes allowed.
29. Front or rear traction bars allowed.
30. Solid rear suspension allowed.
31. REQUIRED: Fire Extinguisher in vehicle.
32. REQUIRED: Kill Switch.
33. REQUIRED: U-joint and drive shaft shielding (loops) (minimum of 1/4 inch steel or 5/16 inch aluminum).
34. REQUIRED: A SFI certified bell housing around flywheel and clutch and no cast bell housings allowed.
35. REQUIRED: A SFI certified scatter blanket or shielding around torque converter and transmission.
36. REQUIRED: A SFI certified steel flywheel and clutch.
37. REQUIRED: A SFI certified harmonic balance or 360 degree shrouding of balance with 1/4 inch steel.
38. REQUIRED: Approved fire suit and helmet.  Neck Brace is optional. 
39. Hitch cannot raise before, during or after the pull.
40. No portion of hitch can be greater than 25 degrees or less than 0 degrees and must be straight plane from hitch point to hook point.
41. OEM intake port spacing and OEM intake must be bolted onto heads while bolted to the motor. OFM valve angle per manufacturer. 
42. $500 to protest motor.