here is what i found on SOUTHWEST WISCONSIN PULLERS website jason. sounds like a legit set of rules to me.
3.0 Diesel
The 3.0 Diesel class is designed for full bodied pulling trucks, the vehicle maybe two or four-wheel drive.
Weight: 8000 lbs. Maximum, with driver.
REGULATIONS:
Ballast: Ballast is permitted. Hanging weights may not extend more than 60 inches from the centerline of the front axle.
Batteries: The batteries must be securely mounted. They may not be located in the driver compartment.
Body: The body must be a full size truck body, including the full bed floor. Alternatively, two one-hundred pound weights may be placed directly over the centerline of the rear axle in lieu of the bed floor. The body must retain full sheet metal. Metal aftermarket hoods are permitted, fiberglass is prohibited. The hood must be closed and securely latched while the vehicle is hooked to the sled. Tilt bodies are allowed but must be securely latched while hooked to the sled. A firewall with a minimum of factory oem gauge sheet metal is mandatory. A full floor pan with a minimum of factory oem gauge sheet metal is mandatory.
Brakes: All trucks must have two working front disc brakes. 2wd trucks must also have working rear brakes. Alternatively driveline brakes may be used. If a front driveline brake is used it must be accompanied by a rear driveline brake or two rear disk brakes. All brakes in the driveline will be shielded 360° with 5/16 steel or 3/8 aluminum, around the brake components. Ends must be enclosed in the 1/8 steel or aluminum, no cast metal permitted to be used as part of shield.
Chassis: The OEM chassis is mandatory. The vehicle must retain the full OEM chassis. Wheel tubs, back-half conversions, tube chassis, etc., are prohibited.
Cooling System: Radiators may not be mounted in drivers compartment.
Credentials: All drivers must have a valid state drivers license.
Driveline: Any front axle, any transfer case, any rear axle. No planetaries permitted.
Driver Restraint System: The OEM restraint system is mandatory and must be worn. Alternatively, a three-inch-wide driver restraint system labeled as meeting SFI Spec 16.1 is permitted; this system includes a crotch strap.
Driveshaft Loops: All trucks must have at least six inch wide u-joint shields around the rear u-joint constructed of at least 1/4-inch steel or 3/8 inch aluminum that will safely contain the u-joint and the end of the rear shaft. All shields must be securely mounted to the vehicle. Any front shaft u-joint that is visible from the side of the truck must be shielded to contain the u-joint and the end of the shaft. On open drive line vehicles the intermediate shafts must be fully enclosed with a 5/16 inch steel or 3/8 inch aluminum shield that must cover the entire length of the shaft and universal joints and yokes at each end, must have u-joint shields on all drive shaft u-joints, must have three loops per shaft that are evenly spaced. All shields and loops will be two inch maximum away from drive line.
Engine: The engine block must have been available as a factory option on a one-ton or smaller pickup truck. Engine may not exceed 460 cubic inches. Front of engine block can be no farther forward than 17” of the centerline of the front axle.
Exhaust: All vehicles must be equipped to direct exhaust straight upward. Two 3/8 inch diameter bolts must be installed through the exhaust pipe in a cross pattern within one inch of each other as close to the turbo as is practical.
Fire Extinguisher System: A fire extinguisher system is required. It must be securely mounted.
Fuel: The fuel must be pump #1/#2 diesel only. Soy/Bio-diesel fuel is permitted.
Fuel Injection Pump: Largest injection pump allowed will be p-pump with 1 plunger per cylinder. All p-pumped trucks must be equipped with a fuel shutoff capable of blocking fuel flow to the injection pump. A three-way dump valve is recommended.
Harmonic Balancer: All engines turning 4500 RPM and higher must be equipped with a harmonic balancer or damper meeting SFI Spec 18.1 or have a shield across the frame under the front of the motor shielding the damper and engine fan area in case of a crank breakage. If a harmonic balancer is not used and a tone ring is in place, a shield across the frame under the front of the motor shielding the damper and engine fan area is required.
Hitch: Trick hitches are prohibited. The hooking point must a minimum of 44” from centerline of rear axle to hooking point. The hitch must be stationary in all directions. The hitch’s height from the ground may not exceed 26 inches on 4wd units and 30 inches on 2wd units. The hooking point must have a minimum 3.50-inch inside diameter opening for the sled hook. Open drivetrain trucks must have a secondary safety hitch. Safety hitch must be as strong as primary hitch and cannot be connected to primary drawbar. Safety hitch must be mounted twelve (12) inches below primary hitch.
Interior: One driver seat is mandatory and must be securely mounted.
Master Cutoff: A sled operated emergency shut off is mandatory. The cable must terminate into a two-inch diameter steel ring. Electronically controlled engine must kill electrical power to the ecm, air shut off suggested. On p-pumped engines, cut off must control three items, shut off injection pump, trip fuel shut off or dump valve, and trip air shut off, all three must also be able to be controlled from driver seat
Nitrous Oxide: Prohibited, along with all other oxygen extenders. All system components MUST be removed from the truck.
Propane: Prohibited. All system components MUST be removed from the truck.
Protective Clothing: Drivers must wear a jacket and pants meeting SFI specifications. Drivers must wear a helmet. The retention strap must be securely and snugly fastened. The helmet must have the appropriate certification sticker affixed inside it.
Rear End: Rear axle bolts must be covered by a cap or shield.
Steering: Must be able to maintain steering of the vehicle if master shut off pulled.
Street Equipment: Taillight assemblies are mandatory and must be operative with brake and reverse lights. Alternatively, vehicles must have a neutral safety light. A white light automotive quality, a minimum of 2 inches in diameter, must be mounted within 30 inches of hooking point and within 6 inches of center line. Also, a light in the driver’s compartment must be operated off the same system. Both lights and the starter interrupter switch will be operated off of the shifter lever. Windshield and windows are mandatory. Driver’s door must open.
Suspension, Front: The axle centerline must remain in the factory location.
Suspension, Rear: Rigid or 4 link systems allowed. May be fully welded.
Tires: The tires must be DOT street tires. Cut tires are prohibited. Maximum tire diameter is 36”
Tow Vehicle: Allowed. Truck must drive on and off the track under its own power.
Transfer Case: Any.
Transmission, Automatic: Aftermarket torque converters, valve bodies and internal components are permitted. Transmission brakes are prohibited. Any non-OEM floor-mounted automatic transmission shifter must be equipped with a spring-loaded positive reverse lockout device to prevent the shifter from accidentally being put into reverse gear. A functional neutral safety switch is mandatory. All transmission lines must be metallic or high-pressure-type hose. All vehicles with engines running 4500 RPM or more and using an automatic transmission must be equipped with a transmission shield meeting SFI Spec 4.1 and must be labeled accordingly. A blanket-type shield is permitted; it must be appropriately labeled as meeting SFI Spec 4.1 and it must extend from the rear of the block to the front of tail housing with a minimum six-inch overlap where it is fastened. All non-blanket-type shields must incorporate two (or one, per manufacturer’s instructions) 3/4 inch by 1/8 inch straps that bolt to the shield on each side and pass under the transmission pan unless the transmission pan is labeled as meeting SFI Spec 4.1. All vehicles with engines running 4500 RPM or more and using an automatic transmission must be equipped with a flex plate meeting SFI Spec 29.1 and be covered by a flex plate shield meeting SFI Spec 30.1.
Transmission, Manual: A clutch meeting minimum SFI Spec 1.1 or 1.2 is mandatory on all vehicles with engines running 4500 RPM or more. All manual transmissions must be clutch assisted. Sequential shifters are prohibited. 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; it must be attached to the block and extend rearward to the transmission with a minimum six inch overlap where it is fastened.
Turbocharger: All Open Drive line configuration vehicles are limited to a single turbocharger with an inducer bore in the compressor housing no larger than 3.0 inches measured at the smallest diameter area of the compressor wheel. Compressor wheel must protrude through housing at least 1/8 inch. All provisions allowing air to the wheel other than via the bore are prohibited. Map enhancement grooves allowed. No MWE groove will be allowed that has a width greater than 1/4 inch. 3.0 inch Twin configuration compound setups are allowed if truck is equipped with factory 1 ton or smaller drive train. Bushings, slugs, cheater rings and clipped wheels are prohibited in all trucks.
Water Injection: Water injection is permitted. Alcohol, methanol, and all other flammables are prohibited. Commercially available pump lube is allowed.
Wheelbase: Maximum wheelbase is 158” for open drive line trucks. OEM drive line trucks may run any wheel base with a factory original unaltered frame with matching original OEM cab and box dimensions. Maximum width is 102”.