Vermont Tractor Pullers Association
Super Stock 4 x 4 Trucks (2017 update) Driver Eligibility:  1. General rules apply.  2. Minimum 16 year old licensed driver. Safety:   1. OEM seatbelt or better must be worn.  2. DOT approved full face helmet with chin strap fastened.  Face shield recommended. 3. No passengers on track or pit area. 4. MANDATORY 2 ½ lb fully charged fire extinguisher on board in reach of operator. A functional gage on the fire extinguisher required. 5. SFI 3-2-A-1 fire suit, fire retardant gloves, fire shoes and head sock MANDATORY.  6. External battery disconnect recommended.  7. All vehicles will be equipped with a working white reverse light.   8. All vehicles must have a neutral start switch on standard and automatic transmissions.  9. All vehicles MUST have a kill switch mounted a maximum of 24” above hook point.  Maximum 12”right or left of center line.  Kill switch must kill electric fuel pump.  10. Automatic transmission-Blanket:MANDATORY 6 strap blanket, minimum SFI 4.1 rating. Straps tight and blanket securely fastened.  Blanket MUST cover 360 degrees from rear of engine block to tail shaft.   11. Automatic transmission-Shields:Transmission shield and flex plate shield MUST meet SFI 4.1 rating.  Composite transmission shield and flex plate shield MUST meet SFI 30.1 rating. 12. Automatic Transmission-Flex plate:Flex plate MUST meet SFI 29-1 rating.   13. Standard transmission:All engines using a clutch/fly wheel assembly MUST run a one piece SFI 6.1 rated containment bell housing.  MUST use a full block saver plate. Material being 3/16” steel or 1/4” aluminum minimum.  One cooling hole will be allowed in the bell housing.  Hole must not be in explosion area.  NO welding will be allowed in explosion area of the bell housing.  NO chemical milling permitted.  All inspect ion and/or maintenance hole must be no wider than 8 1/2” and securely bolted to bell housing.  Bell housing must be bolted to the engine, using all OEM engine bolt holes, grade 5 fasteners or better.  Block saver plates must be securely bolted to bell housing.  All Fly wheel, pressure plate, clutch disc and clutch components MUST meet  SFI 1.1 or 1.2 rating.  Chassis:  1. OEM frame, modification reinforcements allowed.  Maximum 133” wheel base.  2. 4WD trucks MUST have bumper stops mounted on rear of frames to prevent damage from the sled. Engines:   1. Automotive type V8 engine, OEM cast iron block or aftermarket OEM configured cast iron block.  500 cubic inch +/- 1%. 2. At specific events where aluminum heads are allowed, a conventional style aluminum head must be used.  Also 100 pounds of weight located no further forward than the engine and securely mounted  3. MUST use cast aluminum or cast iron manufactured intake manifold.  4. NO homemade manifolds.  NO fuel injection.  5. Engine to be naturally aspirated.  Carburetor limited to one of any size. 6. Engine must be in engine compartment behind radiator and in front of fire wall. Engine location no further forward than center line of engine block to center line of front axle.  All vehicles must have a grill in factory location. 7. Gasoline only.  Nitrous oxide, propane, nitro methane, alcohol, methanol and all other oxygen carriers and flammables PROHIBITED. 8. Engine side shields must cover from top of block to bottom of crank shaft throw. Shields to be full length of block.  Frame rails allowed as part of shield.  Minimum .060”steel or .125” aluminum.  9. All engine fans must be shrouded with 1/16” or thicker steel, 360 degrees, unless equipped with an electric fan.  REQUIRED to have SFI approved harmonic balancer only. 10. MUST have two or more, throttle return springs.  Springs must return throttle butterfly(s) to idle if linkage or cable breaks.  Toe loops on gas pedal recommended. 11. Exhaust must not exit down (dust control).  Drive Line:   1. Transmission, transfer case, front and rear differentials must have come factory in a one ton or less pick up.  Dana 60-70-80 series allowed.  Posi-trac and differential spools allowed.   2. NO planetaries.  NO drop boxes, quick change boxes or quick change rear ends will be permitted.  3. Drive shaft shielding:All trucks MUST have 360 degree, 6 inch long u-joint shields covering rear end yoke, rear output yoke, front output yoke, and front end yoke.  Shield thickness minimum ¼” steel or 3/8" aluminum. Drive shaft loops: Minimum ¼”x ½” steel flat stock.  NO ready rod or chains.  Loops to be mounted 6” from u-joints.  Minimum 2 loops rear shaft, one loop front shaft and securely mounted.   4.  All 4 x 4’s MUST be equipped with axle shields that cover the hubs.  MUST be fastened to the wheel or lug nuts.  Must be made of 1/16” steel or better.  All wheel studs and axle bolts/studs must be used and tight.  5. The vehicle is to be equipped with adequate stopping brakes mounted on the front wheels.   Drive shaft brakes are allowed as a secondary braking system.  Body:   1. Tilt front ends allowed.   2. Lift bodies allowed.   3. All vehicles must have working doors, right and left, securely closed while pulling.  4.  Maximum 3” body lift.   5. Must have OEM glass or lexan in windshield and all other windows.  Tinting of glass allowed.   6. No holes in fire wall or floor boards are permitted except for controls and wiring. Firewall alterations must be equal to or better than the original OEM firewall.  Any firewall or floor pan alterations must use a minimum of 14 gauge steel, 1/8” aluminum, ¼” lexan securely fastened.   No plexiglass allowed.  7. The pickup box must have either a floor that is secured down, made of wood, steel or aluminum, or may use a plastic box liner or custom made tonneau cover securely fastened.  8. Front and rear OEM bumpers and tail gates are optional.  9. No batteries, fuel tank, fuel pump or fuel lines in cab.  Hitches:  1. Minimum draw bar length to be 36% of wheel base.  Draw bar is to be stationary in all directions.  MAXIMUM height of 26” from the top of hitching device parallel to the ground.  Draw bar must be equipped with a steel hitching device not more than 1½” in thickness and with a 3 x 3¾” opening.  Cross sectional thickness must be 7/8” minimum. Pulling point may be no more than 1½” from back edge of the hitching device. Connection point is to be no further forward than the center of the rear axle.    Suspension:  1. Solid blocking, airbags, and timbrens allowed.  2. Traction bars, sway bars, limit straps and aftermarket shocks allowed.  Tires:   1. DOT tires only.  Exception Wrangler XT.  2. Maximum tire width 15.5 (by size marked on tire side wall). No more than 50% of tread width of offset.  3. NO modifications allowed, i.e.: no cutting, grooving etc.  No duals, no studs, and no tire chains.   4. NO military type tires, bar tires or tractor type tires allowed.  Added Weight:   1. All weight must be safely secured to the vehicle and may not extend forward more than 60” from the centerline of the front axle.  No loose weights in the cab or under the hood.  Weight Classes:             5800 lbs with driver and 6200 lbs with driver