General Rules 
Brakes:
1)All competing tractors must be equipped with working rear brakes.
2)All driveline brakes must have a minimum of 3/8” steel, 360 degrees around brake components.
 
Drawbars:
1)Drawbar height to be a maximum of 13” at the inside back of the hole (hook point).
2)Drawbar must have a minimum of 1-1/2” diameter hole.
3)No portion of the tractor may interfere with the sled, chain, or hook during a pull, or while being hooked or unhooked.
4)Drawbar hitching point bolt must be a min. of a ½” bolt, grade 8.
5)Solid drawbar is required for all open class tractors. A solid one-piece hitch of min. 1” solid steel as per NTPA specifications, with a minimum of 1-1/2” hole.
6)Drawbar must be a minimum of 6” long to hook point from the center of the rear axle, with a maximum of 18” long to hook point.
7)Wheelie bars are to be separate from the drawbars.
 
Flywheel and Clutch Shielding:
1. Flywheel and clutch must be wrapped 360 degrees with SFI approved bell housing, or SFI approved safety blanket or homemade shielding 3/16” by 3” wide completely covering the bell housing.
2.  All automatic transmissions must be covered with SFI approved (with sticker) safety blanket and/or shield.  MANDATORY:  The bell housing must be covered with a SFI approved flywheel flex plate shield, or a steel shield that is 3/16” thick by 3” wide.
3. No cast iron flywheels.
4. All planetary gearboxes must be covered with an S.E.M.A. approved blanket or shield.
 
Chassis:
1)All tractors shall have wide front axles.  Front wheels shall track within rear wheels.
2)No portion of any tractor shall exceed 8 foot forward of the center of the rear wheels, except for the tow ring.
3)Tread width (foot Print) not to exceed 6 feet in width. Per NTPA rules 2007 pg. 56
4)Roll cages and seat belts are not required but are highly recommended for all tractors.
5)All tractors must have 4 operational wheels and tires (not flat) upon hooking to the sled.
 
Fuel:
1)All forms of Nitro methane, including Nitrous Oxide, are illegal as fuel or fuel additives for pulling.
2)No pressurized fuel tanks are allowed.

Engines:
1)All tractors require side plates the length of the engine block, 6” above and below the crankshaft centerline, made of 1/8” aluminum or 1/16” steel.
2)Side shields must be mounted independently of the engine block
3)All blow tubes must exit forward of the rear wheels.
4)All pulling tractors must be equipped with mechanical throttle linkage with return to idle springs.  No Hydraulic throttle linkages are allowed.  All foot throttles must have toe straps.
5)All fans and stock type harmonic balancers must be wrapped 360 degrees with 1/16” steel or 1/8” aluminum, and with a crossbar on the front.
6)One-piece harmonic balancers and SFI approved harmonic balancers must be bolted to the crank with a minimum grade 8 bolt.
7)All exhaust must discharge vertically and be securely attached.  Vertical is defined as being within 30 degrees, in any direct of being plumb.
8)No rain caps.
9)All vacuum pumps, water pumps and anything hooked to the engine above the frame rails needs to be shielded same as blower belts.
 
Kill Switches:
1)All pulling vehicles must have a breakaway ignition kill switch in working order at all times.
2)The breakaway kill switch must be mounted in the rear, independent of the drawbar.
3)The breakaway kill switch must break current or ground the ignition circuit as necessary to disrupt ignition to the engine(s).  On vehicles equipped with electric fuel pump(s), the switch must also break the current to the fuel pump(s).
4)All ignition engines must have another kill switch in working order, mounted within easy reach of the driver.  All fuel-injected engines must have a working fuel shut-off valve control within easy reach of the driver.
5)Kill switches will have NO secondary devices securing the kill switch. No electrical tape will be allowed
 
Safety:
1)Tech inspectors can bar from competition any vehicle, at any time, which they believe has a potential safety problem.
2)All pulling vehicles must be equipped with a minimum of one 2-1/2 lb. Fire extinguisher, fully charged and in working order, within easy reach of the driver.
3)All drivers must wear a DOT approved helmet.  Chinstraps must be fastened when pulling.  Loss of helmet is cause for disqualification.  Eye protection is highly recommended but not required.
4)A capable driver must be seated in the vehicle when the engine is being started, and whenever it is running.  Drivers must have complete control at all times. 
5)All pulling vehicles must be equipped with a neutral safety starter switch on the gearshift, which will allow starter engagement only in the neutral or park position. No jumping the neutral safety switch.
6)All tractors with reverse must have a 2” diameter white light on the back of the tractor that automatically goes on when the vehicle is put in reverse. Check if it moves if it does must have light,
7)All drivers must wear fire retardant jackets.
8)Shut down and hands up before measurement and unhooking of the tractor.
9)If the idle is up when leaving the track and tires spin, throwing dirt, the contestant will be disqualified
 
Driveline Shielding:
1)All driveshaft must be covered 360 degrees with ¼” steel or 3/8” aluminum.
2)All chains must be covered 360 degrees with 1/16” steel or 1/8” aluminum.
 
Seats and Fenders:
1)All seats must have a minimum of a 6” high back.
2)Fenders are to consist of a barrier between the driver and tire.  Fenders are to extend a minimum of 4” horizontally from the inside vertical edge of the tire.
 
Wheelie Bars:
1)Wheelie bars are to be a maximum of 6” off the ground, minimum of 2” from the vertical rear of the tire, with 2 bars that have a minimum of a 3” x 3” pad, or a 1” x 5” solid centered wheel, and be able to support the weight of the tractor.
2)All tractors must have bumper bars.  Specs will be the same as the NTPA rules.
     a.In addition to stabilizer bars, there must be a brace that extends vertically 6 inches from the rear most tip of skid pads.
     b.There must be a support brace extending inward to frame, axle, or top of stabilizer bar arms.
     c.Vertical brace should extend rearward a minimum of 2 inches from radius of rear tire.
     d.Material used to build vertical brace and support brace must be the same size and strength as the material used to build stabilizer bar.
 
Tires:
18.4-16.1

Contest is open to pulling vehicles with rubber tires.  NO four-wheel drive.  NO dual tires, tire studs, or chains.  All power must be transmitted through the rear wheels.

Limitations:
1)Maximum 2 valves per cylinder, 1 spark plug per cylinder in all classes
2)No turbine engines.
3)No Coil on plug ignitions. No Digital programmable ignition systems.
4)No Electronic fuel injection. Only carbureted  or mechanical injection allowed (2020)

 

Engine:
1)Maximum of 370 cubic inches small block only. Block must retain OEM bore spacing for that engine family.(2019)
2)One four barrel carburetor or one predator.  No Holley Dominators or fuel injection.  No 4500 style-series carburetors.
3)Tractors may use automatic transmissions with torque converter or gear boxes and clutches(2011)
4)Aluminum heads permitted. Minimum valve angle of 15 degree Part number must be clear for verification (2019)
     a.Heads with less than 15 degree valve angles will not be permitted after 2019
5)No aluminum blocks.  Cast iron only.
6)Roller cams permitted with Hydraulic roller lifters only. No solid roller lifters.(2019)
     a.Hydraulic lifters must be fully functional
7)No coil on plug ignitions. No digital programmable ignition systems (2019)