The Idea or Spirit of the class is to bring ingenuity and limit pushing back to racing and have a place to race and show off their products in a competitive class.
No mixing of rules across classes. Please follow the rules of your prospective class. **Once you enter and race in the leaf spring unlimited class you cannot enter in 
a lower class for the remainder of the calendar season.

Class 2000 unlimited

This class is an open class, and all components will be considered open unless restricted herein. Engine Open.
Forced induction allowed on six cylinders and under.

Doors & Latches

Doors must remain functional and in original stock location with original hinges and working latch. Secondary positive latching devices mandatory if nets are attached to doors.

Chassis & Body
Factory Cab attached to factory frame rails. Factory frame rails must remain intact from rear suspension pivots to front suspension pivots. Frame rails can be cut, notched, sectioned, and reinforced. Suspension mounts can be relocated but must remain hung off factory frame rails.

Trucks with a history of racing in a class that allows fiberglass cabs will be allowed on a case-by-case
base but fiberglass cabs are not encouraged. All other rules must be followed.

Vehicles rear suspension must be supported 100% by leaf springs, spring under or spring over……..
Leaf springs must attach to one solid point on frame and one shackle. Ladder bars, anti-wrap bars, y-link allowed No quarter elliptical systems, air shocks, or secondary style suspension will be allowed.

Front suspension is open, but suspension pivots must remain attached to factory frame rails. 37” Max Tire




Front Suspension

Must be of the same configuration as originally produced. Suspensions may be strengthened and reinforced or fabricated in any manner so long as original stock concept (a-arm, I-beam, etc.)is retained. Lower A-Arms must retain stock pivot points but maybe reinforced. Upper A-Arm pivot points are open. NO J-Arms. I –Beams must mount in factory pivots in the stock location, pivots can be reinforced. Radius arms can be custom and are open on pivot point location. Pivots can be custom, reinforced and/or gusseted. Ball joints may be of any manufacturer. Spindles may be of any manufacture and may be reinforced. After market suspension kits and components are allowed. Pivot mounts may use spherical bearings in place of the stock rubber. Spring buckets maybe clearance to provide room for shocks and coil overs, only minimum frame material may be removed for the purpose of mounting shocks or clearance for steering. Front and rear track width is open.

Rear Suspension

Must utilize an automotive style differential. Rear springs may be relocated to the side of the frame. Frame may not be modified or notched in any manner. Springs may be mounted above or below the axle. Spring rates and capacities are open. Two single point rear differential anti-wrap bars or a single wishbone may be used.

Rear wheel travel limit is 18” axle to frame rail. Stock sway bars may be removed. All suspension components will and can be subject to approval. Hydraulic bump stops are permitted
Air shocks are not permitted.

Aftermarket wheel studs are permitted. 37” max tire size.

Vehicles with 3000 – 4300cc engines must retain the vehicle manufacturers stock CPU / ECU computer and ignition as delivered by the factory. Programming is open. Except Chevy Colorado with 4.3 must remain stock programming.

Safety fuel cells are required.
Fuel cell location is optional. Fuel cell may be sunk into the bed. The rear frame member may be
relocated, removed or replaced in order to sink the fuel cell.



Engine must be one delivered in the vehicle or one that is available from any manufacturer (with the provisions listed herein) from the manufacturer / importing distributor with a maximum of six cylinders. Engine must be available to the general public of the U.S.A. Maximum engine displacement is Stock production 3000cc – 4300cc or modified 2999cc and smaller (187.5ci). Rotary piston engines are not permitted. Water and vapor injection are not permitted. Engine location must be the stock mounting location as delivered from the manufacturer plus or minus 1-inch. Engine mounts are open. This will be measured from the front spindle centerline to the back of the block. Engine Rules
Motor is limited to a maximum of 4.3L 6 cylinder.
Must be a production motor from any manufacturer in any chassis (i.e., Body and motor do not need to match) No High output motors permitted.
This Class has a 300 HP limit in stock form, anything over must be approved.

Restricted items:
A. Intake manifold. (Must remain stock vehicle manufacturers factory intake manifold)
B. Fuel injectors
C. Mass air flow sensor
D. All internal components IE: pistons, cam, crank etc.
E. Block and heads
Unrestricted engine items include:
A. Oil and water-cooling systems. No Dry sumps.
B. Air cleaners – open
C. Fuel pumps – open
D. Exhaust system – open
E. CPU/ECU must be the same as delivered by the factory but programming is open except Chevy
Colorado must remain delivered as by factory with 4.3 Motor
2999cc engine rule
Any make of carburetor or fuel injection may be used but must maintain a maximum of one
venturi per cylinder.
3000cc – 4300cc engine rule
Stock production vehicle manufacturers factory fuel EFI must be maintained as delivered.

Any OEM style transmission may be used T400, T350, C4, C6, etc. No underdrive allowed.
Transmissions subject to the approval by BITD on a per vehicle basis.
Any shifter may be used.

Front differential must remain original stock as delivered by the manufacturer, with the exception of gear ratios. Materials may be added for strengthening purposes only. Front differentials,
including traction beam type, may be reinforced.
Rear axle assembly must use standard automotive style. Housings are open. Gear
ratios, carriers, axles and floating hubs are optional. No gear re-ducted rear ends allowed. Only a single
ring and pinion rear end is allowed. Axles are limited to a maximum of an industry standard 40 spline 1.750” diameter axle.
Knock-off hubs are not permitted.
Any manufacturer’s racing seat may be used but must remain in the stock location.

Dash is optional. It is highly recommended that flammable items such as upholstered panels,
headliners and carpets be removed.
Pedal assemblies must remain in the stock fore and aft position.

Doors must be full doors and must operate on stock hinges and latches. Must have a secondary latching device.

Firewalls must remain stock, complete and in original location. Firewall clearance is permitted only to
make room for transmission. Holes left in stock firewall must be covered with metal and sealed. Firewall
maybe modified for tire and shock clearance and replaced with sheet metal.
Vehicle must weigh dry 3250 lbs. minimum.

Alterations to floorboard, for the routing of exhaust to rear of vehicle, are permitted but floor must remain stock. BUMPERS
Bumpers may be modified. Stock bumpers not required.
Modification must meet with BITD approval.


Specified year chassis and cab combinations of manufacturer must be retained. Front fenders hood, grill
and rear fenders open.

Original wheelbase must be maintained plus or minus 1-inch.
Frame may be strengthened by addition of material but must retain stock configuration.
Lengthening or narrowing of frame is not permitted. Removal of material is not permitted.
Frames may not be altered. Frame rail exceptions:
A. The front end of the frame rail may be notched a maximum of 7 inches from the end for
ground clearance. Top of frame rail must remain stock.

Original body shape, size, configuration and appearance must be maintained. Additional body strengthening mounts or parts may be added. Original stock mounting location (vertical, horizontal, and lateral) in relation to the frame and mounting methods must be retained. The measurement from the spindle centerline to the back of the b-pillar post must remain stock plus or minus 1-inch. Body mounts may be modified for tire clearance.
Internal body structural members may be removed. Clearance holes may be cut or drilled for rollbars, supports, shocks, etc.
Hoods, trunk-lids, doors fenders and bedsides are required to be in original stock locations.
Hoods, front fenders and bedsides may be of any material. Tailgates and pickup bed front panels are optional. Stock front grill assemblies are mandatory.
Safety glass windshields, side and rear glass is optional.