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Pure Stock rules

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This pure stock class is a racing division focused on family participation and is based on rules that will accommodate lower cost and competition. All cars will be subject to re-inspection at any time and if found illegal will forfeit all money and points for that evening. The intent of all rules in this decision is for the safety of all participants. The rules are intended as a guide for the conduct of the sport and are in no way a guarantee against injury, death to a participant, spectator, or officials.  Minimum Age requirement is 13 years of age and up. Ages 13 -17 must have a notarized release form signed by their legal guardian/parent and birth certificate on file.

Minimum Car Weight with Driver after Feature Race: 3300 pounds

Any American made GM or Ford metric frame passenger car, metric framed station wagon, S-10, Ranger pick-up and Novas are permitted. All cars must retain stock wheelbase for make and model. Cars must retain stock steel stock firewalls. Any rusted pieces must be replaced with 20-gauge steel. Trunk area floor pan may be removed inside and outside of frame rails, rearward of wheel houses. Any steel factory style OEM body is permitted, and must have factory hood, truck, and roof.  May replace lower fenders, doors, and quarter panels 4 inches (minimum) below body line with aluminum. (see body diagram pg. 5) Bodies must remain in stock location, or be proportionate to stock location when using an alternate body. Frame must remain square and to factory specs. No Roof Rake.
1. Fenders may be cut for tire clearance. Cutting will not exceed 7 inches of the tire circumference.
2. Front inside fender wells may be removed.
3. Body sheet metal must be in place at the beginning of each race event and kept in an acceptable appearance throughout the season.
4. Doors must be welded or bolted shut.
5. All glass, fiberglass, plastic and trim must be completely removed from the car.
6. Driver and passenger door may be gutted for roll cage installation. No other gutting of car allowed.
7. Hood and trunk must be secured with hood pins at all times. No holes allowed in hood except for hood pin holes. Hood and trunk may be gutted.
8. All openings in car that could present a safety hazard to car occupant must be sealed with 20 ga. steel. 9. BUMPERS: Stock OEM bumpers are required. Option: After-market plastic bumpers may replace stock OEM bumper. A maximum of 2 in. x 3 in. rectangular tubing or 1 ¾ in. round tubing should be used to support plastic bumper. In front of plastic bumper, a wrecker loop is required, may not extend further than frame horns, maximum 2 in x 3 in. rectangular tubing or 1- 3/4” steel tubing, tubing must be capped and rounded with no sharp edges. 
10. Rub Rails: A single rub rail is allowed on each side. Maximum size 1” x .2” maximum thickness 3/16" steel or Lexan bolted flush to body only. Steel tubing must be capped and rounded with no sharp edges. No rub rails are allowed on the rear outside quarter panel area.

1. Any straight or V-6 cylinder or V-8 engine with a maximum 361 cubic inch engine: must remain in stock location. Stock motor mounts are required, may use OEM stock steel replacement motor mounts, which must be bolted into stock location. 4 valve relief Flat top or dish pistons only, must be cast or hypereutectic, no forged pistons.
2. Cylinder heads. Any open chamber cast iron steel OEM factory production straight plug head is allowed that meets the described requirements. (305 ON 305, 350 ON 350, ECT.) No closed nor partially closed chambered heads. No vortec, aluminum or special-order heads. Maximum 1.94 intake valves and 1.50 exhaust valve. Heads may be flat milled for surfacing reasons only. No angle milling. Studs may be pinned or may also use shoulderless screw in studs not to exceed 3/8” on the rocker arm side. No interior deburring or grinding allowed. Casting numbers must remain in heads.
3. Cast iron intake manifolds only. No bowtie, marine, or high-rise intakes. No aluminum intakes (even if OEM for year, make and model came with an aluminum intake). No Brezinski Intake. No port matching intakes or exhausts. No deburring or grinding allowed. No internal modifications of any intake permitted. All casting numbers and firing order must remain unaltered and visible.
4. Carburetor: Unmodified Holley part #4412 only. No Modifications allowed,  Choke butterfly and shaft may be removed and choke horn must remain unmodified, must pass go, no go gauge.  Maximum 1” aluminum spacer/adapter with 1 gasket per side not to exceed .065”in thickness.
5. Any brand, style or size air cleaner is allowed, but no type of RAM air or forced air induction will be allowed.
6. After-market valve cover with breather tubes may be used.
7. Camshaft and lifters Camshaft and lifters must be OEM hydraulic style only; Roller lifters of any type are not permitted. Camshaft lobes not to exceed .300, maximum valve lift allowed is .450”, measured at the valve. Mechanical lifter may be used by tech, for testing purposes. Engine must hold minimum of 14” vacuum at 1200 engine RPM. (.300 with 1.5 rocker arms equal .450 at the valve) 1.6 rocker arms not allowed. Stock or stock replacement fully hydraulic lifters.
8. Stock appearing rods only. Rods should be 5.7” rods only. 3.48 stroke only. ARP rod bolts allowed. 
9. Stock appearing crank only. No lightweight cranks allowed. No knife edge, no bull nosing, undercut or drilling of second or third rod journals throw allowed.
10. Exhaust manifolds must be stock cast iron only. No corvette style (2.5” port exhaust) stock manifolds. No porting, polishing, acid treatment or coatings. Exhaust pipes must extend past driver’s compartment. No Brezinski exhaust manifolds. Must have Turn Downs on Exhaust.
11. Maximum engine cranking compression is 175 psi. For testing, with one or all spark plugs removed from the engine, the engine rotating assembly will be “spun” by the starter for five “hits” on the cylinder being tested and the resulting compression gauge reading recorded for that engine.
12. Must have an oil pan 1” inspection plug between the 2nd and 3rd bolt holes from the front of the motor on the driver’s side to avoid oil pan removal. No obstruction inside of pan.

1. Roll cage must be constructed of no less than 1.5” x .095” steel tubing. Main roll cage and halo must be a minimum of 1” above driver’s head. A minimum of 3 driver’s door bars are required and a minimum of 2 passenger door bars are required. All roll cage welds must be complete.
2. Floor pan may be cut for roll cage installation clearance only. Minimum of 20 ga. steel for replacement floor pans.
3. X bracing under the driver (frame to frame) and sub frame connectors is permitted.
4. Windshield bars must be solid steel bars, minimum 3/8” OD. Windshield bars must extend from upper windshield flange at roof to lower windshield flange at cowl. A minimum of three vertical windshield bars are required in front of driver.
5. Driver must be in stock OEM seating location.

1. All cars must have an ignition switch clearly labeled.
2. The car must have a battery disconnect switch located outside the car and easily accessible to emergency Personnel. If the car is equipped with a working alternator the switch must disable alternator as well.
3. Only one 12V DC battery is allowed. Battery and box must be securely mounted and enclosed if in driver’s compartment or trunk.

Must be securely mounted in trunk of car between frame rails. All cars must have a fuel cell with maximum capacity of 22 gallons. All fuel cells must have a roll-over valve. No plastic boat tanks. You can run gasoline only with no additives.

1. Any automatic stock transmission (powerglide or turbo 350). All torque converters must be Minimum of 10 inches with no modifications. All forward gears must be in working order on all transmissions, with a neutral and working reverse. No over-drive transmissions. Transmission cooler OK but must be out of drivers compartment or shielded to protect driver.
2. Transmission coolers okay, but must be out of driver's compartment or shielded to protect driver.
3. With engine at idle, and brake applied, transmission must accept shift from “neutral” gear to “reverse” gear, and from “neutral” gear to “low” gear, without causing engine to stall. Race car must remain stationary during such shifting and testing. 
4. Standard transmissions must be OEM stock cast iron three or four speed allowed, with all gears in working order and a minimum of 10.5” clutch, pressure plate and full-size stock GM steel flywheel. No mini-clutches, Ram couplers or direct drives. Standard transmissions may not use aluminum flywheel of any size. All standard transmissions must have bell housing made of 1/4” thick steel and must cover 180 degrees over the sides and top of the clutch assembly (also referred to as a blow-proof bell housing). No 5-speed or 6-speed standard transmissions, no overdrive transmissions or overdrive units. No Bert, Brinn or internal clutch style transmissions allowed. Quick-change transmissions or transmission adapters for gear change are not allowed. Car must be self-starting and have working neutral, reverse and ALL forward gears. (ex. 3-speed trans. must have 3 forward working gears.)

All drive shafts must be steel and painted white. Driver shaft must have a safety loop within 6 inches of the front u-joint. No chain loops allowed.

Rear-end must be stock OEM for make and model of car. Any gear ratio is allowed as long as the housing doesn’t have to be altered. Rear end must be locked. Mini spools are OK. No limited slip or posi-traction.

1. Single brake master cylinder only. No brake adjustments of any kind. No valves of any kind. No regulating of brake pressure of any kind (other than the drivers foot). Brake lines must be routed in a manner in which the complete length of line may be inspected by track officials
2. Four-wheel disc brakes OK. No Aluminum brake parts. No Scalloped rotors.  

Must use stock OEM steering for make and model. May use aftermarket steering shaft and quick release. Quick Steer Allowed. No aluminum or after-market gear boxes.

1.  Suspension parts must remain stock for make and model. No modification to any suspension Components. No adjustable or non-adjustable spring spacers. Racing spring allowed maximum height 13” (steel only). Leaf spring cars may use lowering blocks.
2.  Shocks:  Stock Mount/Stock Appearing Shock, No Heim end or Adjustable Shocks.  No take apart shocks/mono tube only.   All Shocks subject to Track Claim
*****SHOCK CLAIM******(full swap, track will provide 4 new shocks, driver will remove questionable shocks and turn over to track official or forfeit race and points)
3.  A-Arm bushings may be replaced with stock style OEM type only. Note:  Bushings may not be steel, mono-ball, nor greaseable type on rear trailing arms or upper/lower control arms.


1. American Racer KK704 or G60
2. 60 Series DOT tires.
3.  8’ Asphalt pull off (grooving & siping allowed). Must be a pull off no new slick tires. Must durameter 51 at end of race.

1.  Maximum 8-inch steel wheel. Beadlock allowed on Right Rear. No light weight wheels permitted.
2.  5/8 studs and 1 inch lug nuts are required.
3.  Wheel spacers are allowed.

Only one radiator is permitted in stock location. Aluminum radiator allowed.

Fuel pump must be stock mount push rod activated. Aftermarket manual type pump is OK. (Example: Carter, AC, Holley)

1. Aluminum racing seats with rib supports are required. Seats must be securely mounted to chassis, not floor pan, with a minimum of four 3/8” bolts. Seat may not be positioned further back than original location.
2. 5-point safety harnesses are required. Required: S.F.I. tag must be legible and no more than 3 years old. Must be bolted to the roll cage and frame with a minimum bolt size of 7/16 inch bolts.
3. A properly installed, full size driver’s side window net is required. Sprint car type window nets are not allowed.
4. All helmets must be a full face, current Snell 90 or newer sticker in it. Snell SA90 & SA00 legal.
5. All drivers are required to wear fire resistant driving suit and gloves. No Nomex coveralls will be allowed. Neck braces are mandatory. Fire resistant shoes are recommended.

Bronco Motor Speedway 2017 PURE STOCK RULES.docx

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