Modified Stock Truck Rules

Modified Stock 4×4 Gas — 6200 lb.

Revised – Jan. 2023

Hitch: Tractor & Truck pullers hitch opening size requirements: 3 ¾ inch front to back and 3 inch side to side. Note: No loose clevis are to be used. Revised – Dec. 2017

  1. Racing gasoline only. No power additives of any kind. Absolutely no Nitrous Oxide, alcohol, or Nitro, etc.
  2. Engine must be same make of truck. Engine center-line rule: center of axle to bellhousing to be at least 12 inches. Any internal modifications to engine are allowed. Revised – Dec. 2017
  3. 472 Cubic Inch Limit Max +/-2%. To be checked with a pump. Must be checked and tagged before 2nd pull. Revised – Dec. 2017
  4. Dry sump oil systems are not allowed.
  5. One single carburetor (4150 or equal) no-dominators.
  6. Aluminum intakes allowed (cast only). No external modifications. Maximum of 2″ spacer between carb and intake. No tunnel rams or sheet metal intakes. Clarification – Dec. 2021
  7. After market heads allowed. Must be cast iron block and heads. No aluminum heads or blocks.
  8. Open headers allowed. Revised – Jan. 2023
  9. Must have alternator; alternator must be driven by crank.
  10. Electric fuel pumps allowed. One fuel pump total. No belt drive pumps allowed.
  11. Electric fans and water pumps are allowed.
  12. Front end and rear end no larger than 1 ton.
  13. Transmission and transfer case must be OEM style of truck. No Pro-Fabs.
  14. Tractor & Truck pullers hitch opening size requirements: 3 ¾ inch front to back and 3 inch side to side. Note: No loose clevis are to be used. Revised – Dec. 2017
  15. All trucks must be teched and pass inspection and display an AFPA tech sticker for the current pulling season. New – Dec. 2021

General Rules

  1. Officials have full and final say over all rules.
  2. Class is open to all persons 16 years of age or older with a valid driver’s license. Anyone under 18 years of age must have a release and consent form signed by parent or guardian.
  3. Officials reserve the right to disqualify any participant that is acting in an unsportsmanlike or unsafe manner. If disqualified, the participant will be subject to removal from the event grounds without refund.
  4. Any driver who is suspected to be under the influence of alcohol or drugs will not be allowed to participate.
  5. Any questions or concerns should be addressed at the driver’s meeting.

Protest Rules

  1. Engine cubic inch protest fee is $300. This fee must be filed at time of protest. The protester is to be checked first. Only top 3 finishers can be protested for engine cubic inch. Engine will be pumped only, no teardowns. If legal, owner of the truck gets $250, and pump operator gets $50. If illegal, protestor gets $250 back and pump operator gets $50. All points and prize money for that pull will be forfeited and protestee barred from pulling at club sanctioned pulls for one year, if truck found to be illegal or refusal of  pumping. Only 3 people can be present during pumping.

Safety Rules

  1. Must have loops on all drive shafts and U-joint shields. 3 on rear and 2 on front.
  2. A working kill switch. Kill switch must be accessible to sled in plain view of sight. Kill switch must shut off fuel pump and ignition.
    Revised – Dec. 2017
  3. Must have Neutral safety “white” light visible by sled operator.
  4. Must have fire extinguisher within hand reach.
  5. Blow proof bell housing or blanket and flywheel shields are insurance required.
  6. Must wear a helmet. Seat belt is required.
  7. NO HOT RODDING IN PIT AREAS.
  8. Driver use of a race seat with five point harness recommended.

Body Rules

  1. Must have all factory sheet metal. No fiberglass or aluminum body parts (exception fiberglass hood allowed). Hood scoops are allowed. Do not have to have a tailgate on truck.
  2. Maximum wheelbase is 135 inches.
  3. Full factory stock bed-NO FLATBEDS or aluminum beds.
  4. No extended cabs.
  5. Inner fenders must be in truck in stock location.
  6. Gas tanks must be in factory position or fuel cell only in bed of truck or on weight box. Revised – Dec. 2021
  7. Must have at least 1 OEM style shock per wheel. Clarification – Dec. 2021
  8. Rear brakes an option.
  9. One battery must be secured under hood.
  10. Stops must be in the center of the axle housing. NO solid suspensions. Springs must have a minimum of 5 working leafs on each side. Springs must be in factory location.
  11. Ladder bars may not extend past the front of bed on the rear or past the front cab mount of the front.
  12. Maximum of 33×12.50 DOT tires mounted on maximum 10″ wide rims. No cut or sharpened tires. Allow only (4) tires. Clarification – Dec. 2021
  13. Front weights may not extend more than 195 inches from center line of rear axle to furthest point.
  14. Hitch will be 24″ high maximum. No less than 36″ from center of the rear axle to hook point. Hitch must fasten to frame only and adjust off the frame ONLY. All bracing must hook to frame or stops that come off of frame ONLY. Hitch opening size 3 ¾ inch front to back and 3 in side to side.