2020 4500 Small Block Modified Trucks
The rules promulgated in these rules are intended as guidelines for the sport of Modified 4×4 truck pulling. These rules have been adopted by Full Pull Productions, Inc. for the 2020 season. Nothing herein should be construed as a guarantee against injury or death to participants, crewmen, family members, bystanders or spectators. Each participant at a Full Pull Productions’ pulling event must assure that their equipment and replacement equipment throughout the season meets the requirements for this class.
4500Lbs. Maximum weight with driver. All vehicles must cross the scales prior to participating. Fuel and water may not be added after crossing the scales – except if qualified for a pull-off.
- A single 4 barrel carburetor mass produced naturally aspirated 4150 style. A Two – Two Barrel Carburetor is permitted (NO PREDATORS, DOMINATORS, OR EXOTIC CARBS ALLOWED) No fuel injection
- Aluminum intake is allowed NO tunnel rams. NO sheet metal intakes.
- Gasoline or racing fuel is permitted no alcohol
- NO BLOWERS, TURBOS CHARGERS, NITRO OXIDE, OR OTHER COMPRESSED GASES.
- Small block engines 360 CUBIC INCHES. (No LS or HEMI type Blocks.) The formula for calculating the cubic inch displacement of any piston engine is: bore x bore x stroke x 7854 x number of cylinders.
- Provisions must be made to put on a “seal” on the engine after the truck has been cube checked. Competitors must be able to have their engine pumped at any time during the pull season. A 1% variance will be permitted.
- Officials may (at their discretion) use a pump or other means to check cubic inches. Competitors must have all tools/equipment to comply with cubic inch check at all pulls. The USA-East protest rule will be in effect for this class of competition
- Any heads are allowed but must be OEM valve angle. Note: No LS or Hemi Style Heads
- SFI harmonic balancer is required
- SFI flex plate and flywheel is required
- Engine fans must be completely shrouded with steel 1/16” or thicker. Electric fans excluded
- All exhaust systems must discharge vertically (vertically is defined as being within 10 degrees any direction of being plumb down style must discharge straight back.)
- No rain caps permitted.
- After market ignition is allowed.
- Rear of engine block can be no far further than the center of the front rear and engine must be behind the factory grill location.
TRANSMISSION AND DRIVE LINES
- All universal joints MUST be covered with 6 inch wide 1/8 inch steel or 3/16 inch aluminum.
- All drive shafts MUST have a midpoint safety loop.
- Any OEM transmission and transfer case can be used, no aftermarket gear boxes or t-cases
- All Automatic Transmissions must use a properly attached blanket that completely covers the bell housing. It must be attached to the block and extend rearward to the transmission with a minimum six inch overlap where it is fastened.
- All automatic transmission MUST have a positive reverse gear lock out. All transmissions MUST have a neutral safety start switch (standard can work off of a pressed in clutch)
- All vehicles equipped with a manual transmission must have a flywheel shield labeled as meeting minimum SFI Spec 6.3 or greater. Applications for which an SFI Spec flywheel shield is not available may use a properly attached SFI 4.1 or 4.2 blanket that completely covers the bell housing may be used in place of the shield; it must be attached to the block and extend rearward to the transmission with a minimum six inch overlap where it is fastened.
- Both front brakes must work and driveline brakes are permitted
- Slipper clutches and high stall torque converters are permitted
- Positivity no Grey Cast Clutch Materials Allowed.
BODY AND CHASSIS
- Maximum wheel base of 135. Must have been a factory 4×4.
- Vehicles must have closed doors, unless equipped from factory with fabric top.
- Half cabs must have closed doors.
- Vehicles must have stock appearing grill, hood, front fenders, bedsides, and hood (can be cut but must shield all rotating parts)
- No weights or any part of the vehicle can extend forward more than 60 inches from center of front axle
- Fuel cell must be located OUTSIDE of the cab with a marked easily accessible fuel shut-off valve.
- If the battery is mounted inside the cab must be shrouded with steel or aluminum cover with a driver accessible battery shut off clearly marked.
- Must retain all exterior body panels fiberglass is permitted. Tailgate not required
- Fenders may be cut for tire clearance only, axle must be positioned within 6” of center of wheel well.
- Must have windshield and drivers window. (Driver’s window must be up while pulling).
- Floor and fire wall area must be covered and no holes larger than 1 inch.
- Any motor, frame, body combo can be used; Tube frames are allowed but must be inspected by current tech official before permitted to pull. 2”x.120 wall thickness minimum
WHEELS AND TIRES
- D.O.T 33/14.5 or equivalent
- 29/11 dirt track tires are permitted
- No bar tires permitted, sipping and sanding of tires is permitted for the purpose of resurfacing only. Cleaning up existing tire grooves allowed.
- Rear tires can be offset inward to center of front tires, no duels. Tire tracks must half lap.
- No Recaps.
- Solid suspension is permitted in the rear.
- Ladder bars are permitted.
- Hitch must be rigid in all directions
- Hitch plate is to be 3 inches wide and 4 inches long inside dimension. ½ inch thick at any point.
- Hitch height will be 24”
- Minimum hitch length is 27% of truck overall wheelbase no shorter than 24”. Measurement taken from center of axle tube to hook point.
- Hitch pivot or attachment point cannot be any further forward than the center of the rear axle
- Driver must wear SFI approved fire suit with Fire Shoes or Leather Boots
- Driver must wear a helmet meeting Snell 85, 90, 95, 2000, K98
- All vehicles must be equipped with at least a 2 ½ pound dry chemical fire extinguisher
- All drivers must be at least 16 years of age.
- Anyone considered being under the influence of drugs or alcohol will be barred from the event.
- Poor sportsmanship or horseplay in the pit area or on the track will not be tolerated.
- All vehicles must have a driver in the seat when motor is running.
- The OEM restraint system is mandatory and must be worn. A five point safety harness is highly recommended in the class
- Driver must have at least one hand at the 12 o clock position at all times while pulling
- The kill switch must break or ground the ignition circuit and must break electric power to an electric fuel pump(s) if so equipped.
- Kill switch must have a minimum 2” diameter solid welded ring, with minimum 1/8” cross section thickness. Must be mounted within 6” of center.
REVERSE SAFETY LIGHT
- A reverse safety light system is required on all pulling vehicles. A white light, automotive quality, minimum 2” in diameter, and must be mounted directly above the hook point at the rear of the vehicle
ANY QUESTIONS FEEL FREE TO CALL THE CLASS REPS:
JEFF JOHNSTON—-814-229-8150 cell 814-457-5022 home