STREET MODIFIED DIESEL TRUCKS
8,200 lbs. Diesel Trucks Only
DOT registration and license plates are mandatory.
8,200 lbs. Maximum, with driver.
Weights are permitted. Hanging weights may not extend more than 60 inches from
the centerline of the front axle.
The batteries must be securely mounted. They may not be located in the driver
compartment or forward of the radiator core support.
The body must be an OEM truck body, including the full 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. The complete OEM firewall and complete OEM floor pan is
Four-wheel hydraulic brakes are mandatory.
The OEM chassis is mandatory. The engine must be in the OEM location for the
body used. The vehicle must retain the full OEM chassis. Wheel tubs, back-half
conversions, tube chassis, etc., are prohibited.
Radiators must be in the vicinity of the stock location and be of at least stock
All drivers must have a valid state driver’s license.
An OEM transmission and transfer case is mandatory. They must have been an
option on a one-ton or smaller pickup.
The OEM restraint system is mandatory and must be worn.
All trucks must have a minimum of 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.
The engine block must have been available as a factory option on a one-ton or
smaller pickup truck. Blocks must circulate coolant freely. Water pumps must be
present, but may be powered electrically. The use of concrete or other block
fillers is prohibited. All factory belt driven accessories, excluding the air
conditioning compressor, must be retained and powered via the crankshaft by a
standard serpentine or ‘V’ belt. Electric fans are permitted. Aftermarket
radiator assemblies are permitted, but must be securely mounted in the same area
as the OEM unit.
OXIDE is prohibited along with other oxygen extenders and the use of
PROPANE is also prohibited. All system components MUST be removed.
All vehicles must be equipped to direct exhaust upward. The exhaust must exit
rear ward of the driver’s compartment. Stacks exiting through the hood or
fender-well are prohibited. 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.
Extinguisher System: A fire extinguisher system is permitted. It must be
The fuel must be pump #1/#2 diesel only. Soy/Bio-diesel fuel is permitted.
Off-road diesel fuel is prohibited.
The fuel injection pump is limited to a stock-appearing, OEM engine
make-specific pump only. Dual high-pressure common-rail fuel pumps or HPOPs are
permitted. The P7100 injection pump, if equipped, must utilize a stock-appearing
All engines turning 4500 RPM and higher must be equipped with a
harmonic balancer or damper meeting SFI Spec 18.1.
The hitch must be a receiver-style hitch; reinforcements are permitted.
Reinforcements must not extend forward of the centerline of the rear axle. Trick
hitches are prohibited. The hooking point must be the rear-most point on the
vehicle and must be rearward of the stock location of the tailgate. The hitch
must be horizontal to the ground and stationary in all directions. Bumpers may
be notched or removed. 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 3.750-inch inside diameter opening for the sled hook. The hooking point
will be measured to the center of the clevis loop.
A complete interior, including dashboard, door panels, headliner, etc., is
mandatory. Two matching front seats are mandatory. Aftermarket seats are
permitted; they must be fully upholstered. All factory controls (lights,
signals, horn, windows, wipers, etc.) must be retained and operative. The use of
a hand-throttle is prohibited.
Non-OEM rear-end housings are prohibited. The rear end must have been an option
on a 1-ton or smaller truck. Rear axle bolts to be covered by a cap or shield.
The vehicle must retain the full, original OEM steering gear. The vehicle must
retain the original OEM power steering assistance, if it was so equipped.
Additional stabilizers are permitted. Non-OEM power assist methods are
Complete headlight and taillight assemblies (all) are mandatory and must be
operative. Complete OEM windshield and windows are mandatory. Windows must be
operative per factory specifications; that is, they must open and close via OEM
electrical or mechanical means. Driver’s window must be completely
rolled up while competing. Other windows on truck may be lowered.
The factory suspension configuration must be retained. The upper mounting point
for strut assemblies must be in the factory location. Adjustable caster/camber
pillow ball mounts are permitted. The lower control arm may be strengthened
provided factory-mounting points to chassis are maintained. The lower mounting
point for the strut assembly may be modified for improved caster or camber.
Strut tower braces, lower tie bars, sway bars, and limit straps are permitted.
Traction bars and devices are permitted.
An OEM-style suspension is mandatory. Traction bars and devices are permitted;
they must be bolt on only; welds are permitted for attachment to frame or axle
housing. Control arms may be strengthened or replaced, provided all original
mounting points are retained. Strut tower braces, lower tie bars, sway bars,
limit straps, and camber kits are permitted. The rear suspension may be bolted
solid to eliminate travel. All rear suspensions must use at least one working
shock absorber per wheel.
The tires must be DOT street tires. Cut tires are prohibited.
Non-OEM transfer cases are prohibited. It must have been an option on a one-ton
or smaller pick up truck.
Non-OEM transmissions are prohibited. 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
Non-OEM transmissions are prohibited. Aftermarket internal components are
permitted. 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 with engines
running 4500 RPM or more and 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.
The vehicle is limited to a single turbocharger; the inducer bore on the
compressor housing may be 2.6”. The inlet will be measured using a
2.65-inch plug or internal calipers. Bushing from any larger turbo size down to
a 2.6 turbo is PROHIBITED. A stock map width enhancement (MWE) groove is
allowed. No MWE groove will be allowed that has a width greater than 1/4 inch.
All provisions allowing air to the wheel other than via the bore and the MWE
groove are prohibited. 6.4 liter Powerstroke engines may utilize the factory
Water injection is prohibited. All system components must be removed from the
The vehicle must retain the original unaltered factory wheelbase and track
width. Front dual-wheel spacers may be used only with accompanying
positive-offset dually style wheels.