2019 – Pro Stock Rules
Rules have been completely revised for 2019, consider all rules as revised from 2018.
Variations from any specification or rule must be approved by the speedway tech officials.
- This division was created as a controlled, economical and competitive form of racing.
- Any North American made car 1968 to present. No jeeps, station wagons, compact cars, trucks, four wheel drive vehicles, convertibles or Corvettes.
- NO ENDURO CARS.
- Must have operational 4 wheel brakes. ROTORS MUST BE STEEL.
- Car Numbers must be at least 18″ high and 2″ wide and painted on both sides.
- No rear view mirrors of any type.
- Frames MUST remain STOCK APPEARING.
- Frame rail front to back must be constructed with a minimum of 2” x 3” box steel with 10” circumference and 0.090” minimum thickness.
- Cars with uni-body construction must be connected from the rear of the front clip to the front of the rear clip.
- 2” x 3” frame material can be used to replace stock frame or to tie a uni-body chassis together. Must be 0.090” min. thickness front to back.
- Roll cage must be of a four post design. Top of roll bar must be connected to form a box section and be at least four inches above driver’s head. Bars must be securely fastened to FRAME by WELDING. No screwed pipe fittings allowed. All roll bars must be a minimum of .090 wall thickness. Seamless tubing of 1-1/4” or seamed tubing of 2″ outside diameter must be used. Must have at least 3 door bars on driver’s side and 2 door bars on passenger side.
- Bracing around engine and radiator required with a maximum 2″ tube. One loop must be used with bracing allowed on each side from loop to frame and must be tied into main roll cage.
- Bracing must be kept inside fenders. No bracing may extend beyond bumpers. No sharp edges allowed.
- 2 bars must run from top of roll cage to rear frame. Bracing must be inside trunk.
- Cars must have securely fastened front and rear bumpers AT ALL TIMES! Rub rails are not permitted.
- NO EXTREME BRACING ALLOWED
- Strut plate on strut cars may have slotted strut mounting holes.
- Only stock type suspension is permitted. All springs must remain in stock location.
- Weight jacks can be used.
- Steel top tubular “A” arms may be used. Bottom A-arms must be stock. Aftermarket upper “A” arm mounts are allowed.
- Ford and Mopar may run full frame with all stock chassis components.
- Steel rod ends can be used in steering links.
- Only stock OEM spindles. NO wide five spindles.
- All suspension parts must be stock or stock type replacement.
- Rear leaf springs may be mounted with no more than a 3” maximum difference front to rear.
- No leaf spring slider mounts permitted.
- No leaf spring weight jacks permitted.
- Must use weld-on stock type spring pads. No birdcage type mounts are allowed.
- All stock and aftermarket spring pads must be fully welded to the axle tube.
- Stock type triangulated 4 link or leaf spring suspension only.
- 4 link cars must use steel stock length upper & lower trailing arms with steel heim ends.
- Springs must mount on top of axle tubes with a 2” offset tolerance.
- All 4 links must be connected at all times.
- Leaf springs must be steel multi-leaf. NO mono leaf springs. NO composite leaf springs.
Rear Suspension Continued:
- Lower spring plates must remain stock and unaltered. Leaf spring centering bolt hole must remain untouched.
- No Material is to be used under or between the U-bolts and the axle tube.
- No torque arms, birdcages, lift bars, pull bars or pan hard bars allowed.
- Rears can be dropped and blocks are permitted under rears.
- No adjustable blocks under rears.
- No adjustment or adjustability of suspension components in any way.
- NO independent rear suspensions.
- Heim end shocks are allowed
- NO bump springs are allowed.
- Must be non-adjustable steel bodied fixed end shocks.
- Shocks can be oil or gas filled.
- Any shock having a gas port, Schrader valve or bladder type valve must have the valve plugged.
- Non strut cars may move front shock mounts to the outside of the A-arm.
- No coil over shocks anywhere.
- No reservoir shocks allowed.
- Strut cars must use the strut shock or drill out the strut shock and mount a perpendicular shock to the strut. Cannot be both at any time.
- All springs and spring pockets must remain in stock location.
- Steel leaf springs only, must be stock appearing and full length.
It is recommended that all engines be pumped, whistled and have a Clinton County Motor Speedway seal attached before entering competition. Having this done is mandatory after two races.
Options for engines inspection and sealing other than during a post race technical inspection. ALL options require advance scheduling with Speedway tech officials.
- At one of the scheduled Speedway tech days.
- At the speedway on race day. (1 week advance notice required)
- Scheduling a shop visit with Speedway tech officials.
Engine – General
Displacement: 358 Cubic Inch (plus a 3 cubic inch tolerance) is MAXIMUM displacement allowed.
Compression: ALL ENGINES, 11:1 Compression Ratio MAXIMUM with track whistle box.
Pistons: Flat top pistons only.
Exhaust: Headers permitted.
Oiling System: NO dry sump systems allowed. Wet sump must be used.
Fuel: Racing gasoline only. No alcohol. No additives. NO oxygenated race fuels.
Engine – Block:
- Block must be a standard OEM production block or aftermarket. No aluminum blocks.
- Chevy engines must use a Generation 1 style.
- Block Casting Numbers must be in place
Engine – Rods:
- Any steel rod (No titanium or aluminum) may be used.
- Rods, block, and crank to be used in the same combination that factory originally manufactured.
- Any stock dimension steel rod (No titanium) may be substituted. Stock dimension includes length, wrist pin location and journal size. Aftermarket rods must be in factory condition.
- No polishing or reworking.
- No addition or removal of metal other than normal balancing.
Engine – Heads:
- Aftermarket steel heads are permitted. No aluminum heads. Standard valve angle per manufacturer.
- Chevy engines must use a 23° Generation 1 style cylinder head.
Engine – Cams:
- Only hydraulic or solid flat tappet cams are permitted.
- No roller cams or roller, radius, or mushroom lifters permitted.
- NO 4-7 swap camshafts permitted. STOCK OEM FIRING ORDER must be maintained.
Engine – Valve Train:
- NO titanium valves
- NO shaft rockers permitted.
- Roller rockers are permitted.
- High valve covers are permitted.
Engine – Crankshafts:
- Any stock appearing cast iron or forged steel crankshaft is permitted. (No titanium)
- No polishing or reworking.
- No addition or removal of metal other than normal balancing.
Engine – Carburetor:
- Mechanical fuel pumps only.
- NO electric or belt drive fuel pumps permitted.
- Limited to One 2-barrel 500 CFM HOLLEY. Must use part #0-4412. No Predators, No Dominators. Holly Ultra carbs are permitted.
- NO modifications allowed except for jet changing.
- Must fit track Go-No/Go gauges. Only the choke plate may be removed with all screw holes permanently sealed.
- Four barrel aluminum intake is permitted. Adapters permitted.
- NO adding of material to top of intake allowed. Must be Intake, Gasket, Adapter, Gasket, and Carburetor.
- Adapter Thickness 1-1/2 inches Maximum 1 stock gasket above and below adapter plate.
Engine – Ignition:
- Stock type HEI ignition only.
- No MSD Super Coils, Blasters, Pro Coils, Power Coils allowed. No Billet Distributors allowed.
- No multiple spark boxes.
- 12 volt systems only. Voltage will be checked at the distributor.
Engine – Setback:
- Engine setback will be measured from face of rear end housing to back of engine block.
- Measurements will be dictated by wheelbase as follows:
- Wheelbase is measured from center of the ball joint grease fitting to center of axle tube.
- Minimum wheelbase is 103”
- Maximum wheelbase difference from side to side is 1”.
If car measures 104” on left side,
- maximum wheelbase on right side is 105”
- minimum wheelbase on right side is 103”.
- Ford 9″ rear optional with mounts in stock location on any model car. (No floater or fast boy setups)
- Grand National type rears (with floating axles) are allowed for safety with mounts in stock location on any model car.
- Stock and/or stock type aftermarket spring pads only, must be fully welded to the axle tube.
- Rear ends cannot have any type of built in camber adjustments.
- Rear ends cannot have any toe in or out built into the housing. Hubs must remain at 90° to the axle tube in all directions.
- Absolutely no tampering with axle tubes.
- No camouflaging of rear axle tubes allowed.
- Stock transmission or stock style replacement.
- No 1:1 late model style transmissions allowed, (BERT, BRINN, FALCON, ECT.)
- Steel blow proof bellhousing MANDATORY with one – 2 inch diameter inspection hole located in the 6 o’clock or 12 o’clock position. Dust covers must be easily removed for tech inspection.
- Hydraulic throw-out bearings are allowed.
- No straight cut gears or lightweight gears allowed in any transmission.
- Transmission must be GM to GM, Ford to Ford, etc.
- Must have working reverse.
- No aluminum flywheels.
- No Coupler type clutches.
- Clutch must be working at all times.
- Multiple disc clutches are allowed.
- Drive shaft loops required.
- Drive shaft must be painted WHITE.
- No automatic transmissions
Body – Interior:
- Car must have a complete floorboard; area under driver should be reinforced.
- Rear deck behind driver may either be flat or run up hill to front of deck lid, either way it must be of one flat plane and cannot be used as a spoiler.
- NO boxing in of the driver’s compartment is allowed. Area can remain open door to door or sheet metal must run on a 45 degree angle away from the driver from the top of the drive shaft tunnel to top of right door.
- All glass must be removed. No windshields are permitted. No broken glass may be in any part of car including door panels.
- Window screens are mandatory in place of windshield. These must be secured with three (3) supports.
- All flammable materials must be removed from car.
- Firewall must be completely enclosed. No open holes.
- Cars must have a complete firewall between trunk and driver.
Body – General:
- Bodies may be constructed of aluminum or steel panels.
- Body must resemble an OEM stock body with OEM appearing body panels, body lines, curves and shapes, including nose.
- Maximum body width side to side is 76 inches.
- Front fenders should gradually slope down to nose.
- Body panels must match the shape of nose used, Example; Camaro nose car MUST have a Camaro shaped body etc.
- All cars must have a minimum of one inch (1”) and a maximum of two (2”) inches of roll at top of fenders, doors, and quarter panels. NO squared off or 90 degree bends anywhere on the body.
- All bodies must be in good condition, stock appearing and securely fastened.
- Bodyline must be a smooth even line from front to rear. All body panels must be solid. No holes, slots, or air gaps are permitted.
- Fiberglass or metal roofs are permitted. Roof must be stock appearing, mounted level, parallel to body, centered on car and rounded down in all directions.
Body – General Continued:
- No wings or spoilers or a trunk lid that appears to look like one. No fins or raised lips of any kind are permitted anywhere along the entire length of the car.
- Area between bottom inside of deck lid and “top” of main frame rail must be permanently closed in.
- The fuel cell can be lowered and placed between the frame rails. BUT it may not sit lower than the center of the rear end and must have a hoop welded under the bumper protecting it.
- No “belly pans” or any type of enclosure on bottom of cars will be permitted.
- Skid plate to protect oil pan is permitted.
- No panels of any kind under the rear deck running from the front to the rear of the car.
- Race cars must be safely maintained and kept in presentable condition.
- No “slope” or “wedge noses” permitted. (See section on nose covers and fenders.)
- Stock appearance will be at the discretion of track officials.
Body – Nose Covers and Fenders:
- Sloped front noses (Late Model MD3 or Late Model style noses) will not be permitted.
- Nose cone on car must resemble an OEM nose (ie: Camaro, Monte Carlo, Mustang, T-Bird,etc)
- Front nose and front fenders should not extend beyond outside edges (sidewall) of front tires. 100% of front fender from rear edge of nose cover to front tip of door must be made of sheet metal. NO plastic, NO elephant ears, Late Model style elephant ears or plastic fenders will not be permitted.
- Stock appearance will be at the discretion of track officials.
- If nose of car comes into question team must produce proof of manufacturer and model.
- Nose measurement is from center of spindle to front tip of nose. Measurement is 46 inches. NO tolerance allowed.
- The nosepiece must be mounted in a manner that does not alter its original shape.
- Plastic bumpers permitted front or rear providing they cover a steel bumper.
Suggested Molded Plastic Noses:
|Five Star – Stock Appearing Noses|
|81, 92, 97 Camaro||Fusion – Taurus||Toyota Camry|
|94 Lumina||03 Taurus||Dodge Charger|
|93 Mustang||88, 97 Thunderbird|
|88, 99, 03 Monte Carlo|
|Chevrolet SS Monte Carlo|
|03 Grand Prix|
|97 Olds Cutlass|
|97 Buick Regal|
|Performance Bodies – Stock Appearing Noses|
|Early Style Camaro||06 Taurus|
|Z-28 Camaro||88, 97 Thunderbird|
|92 Camaro IROC-Z||79-93 Mustang|
|81-88, 99, 05 Monte Carlo|
|03 Grand Prix|
Body – Sail Panels:
- Must resemble size and shape of factory OEM panels.
- Sail panels must be flat front to back and top to bottom.
- 18 inch maximum at top, 24 inch maximum at bottom.
- Rear of panel must line up with rear corner of roof
Body – Roof:
- Roof Height must measure the same at both right and left “A” pillars.
- No more than 2” of rake front to back
- Minimum roof size is 44 inches long by 46 inches wide.
- Maximum roof size is 55 inches long by 53 inches wide.
Body – Rear Quarter Panels:
- Must measure the same height on both sides.
- Bottom of panel must angle up to back a minimum of 4 inches.
- Panels cannot stick past 45 inches straight back from center of rear axle.
Body – Rear Filler Panel: Between the quarter panels must be solid corner to corner. No “V” shaped rear panels.
- Hosier or American Racer
26.5/8.0-15 SCL Medium, Hard
27.5/8.0-15 NRM Medium, Hard
- All factory sidewall markings must remain intact and visible at all times.
- No grinding, buffing, altering, or attempt to alter any sidewall designations or markings is permitted.
- Tires found in violation or that are missing any information for any reason will be considered illegal.
- Cars found to have an unapproved tire (s) or an illegal tire (s) will cause the car and drive to be disqualified.
If discovery is made during any race or time trial or during any post race or time trial technical inspection, the car and driver will be disqualified, scored last for the race and will not be permitted to participate in any remaining races scheduled for the event. Both car and driver will also forfeit any and all championship points, awards and prize money for the event.
- Steel wheels only
- Eight (8) inch maximum rim width.
- All wheels must be reinforced and be attached with oversize lug nuts.
- Steel beadlocks are allowed.
- Total weight of car and driver may not be less than 2,900 pounds. Weigh-in to be after any event or qualifying. Weight to be measured as car comes off the track in the condition that it took the checkered flag.
- Strut cars must have 35 lbs bolted from rear of engine forward. Maximum of two (2) weights.
- All weight is to be either welded or properly secured to the car with no less than grade 8 bolts and lock nuts.
- All weight must be contained under the body.
- Weight measured by Clinton County Motor Speedway scales.
- Any car that completes a time trial, finishes in the top 3 of any heat, top 5 of any main event, or otherwise as directed by speedway officials MUST go directly to the scales first before the car stops with the crew and/or at the trailer will be disqualified and scored last for that event.
- Track officials may request that you shut off the engine of your car while on the scale. Driver must remain still in the seat while car is being weighed. Any car that is deemed light will be reweighed a second time. The car in question will be rolled off the scale by hand, the scales will be reset and the car immediately rolled back onto the scale by hand. Cars will not be permitted to leave the on/off ramps of the scale between reweighs unless directed by track officials. Any car required to be weighed at the completion of any event that does not meet the minimum weight requirements will be disqualified and scored behind all other cars that were on the track at the end of the event. The number of cars required to be weighed for any event may be changed by track officials and teams will be notified.
- THE READING ON THE SPEEDWAY SCALES ARE FINAL.
- Any car required to be weighed at the completion of any event that does not meet the minimum weight requirements will be disqualified and scored behind all other cars that were on the track at the end of the event.
- The number of cars required to be weighed for any event may be changed by track officials and teams will be notified.
- Pro Stocks are required to use transponders. Rental units are available from the speedway.
- Transponders for Pro Stocks must be mounted in the cockpit and no less than 80″ from the center nose of the car.
- Transponders must be mounted in a vertical position pointing straight down and as close to the ground or floor pan of car as possible. There cannot be any metal, carbon fiber or other material that would deflect or block the signal between the transponder and the ground. A hole must be cut in the floor pan, directly under the transponder, that is large enough to allow the signal to reach the ground. Size of the hole may vary based on the angle the signal leaves the transponder and the height of transponder mount above floor pan.
- Other than wiring used to connect direct powered units the transponder should not be mounted within 12″ of any device that generates, transports or stores electric or magnetic energy (individual race cars may require a greater distance or shielding). Mounting recommendations are to the roll cage or to a bracket welded to the floor of the car. Transponder should be mounted as far to the right in the cockpit as possible although in all cases transponders must be mounted inside of the area contained by the roll cage. Transponders/brackets should be riveted, wire tied or clamped to the mounting point with additional wire ties, clamps or other securing devices encompassing the entire mounting point / bracket / transponder for additional security.
- Speedway is not responsible for lost/damaged transponders. Damaged/Lost units rented from Speedway are the responsibility of renter.
- It is each race team’s responsibility to ensure that the transponder they are using is mounted properly and in working condition at all times car is on track.
- Changes in mounting location may only be approved by speedway electronic scoring technicians and only in the case of transponders not reading correctly. This shall only be approved if it is determined by speedway electronic scoring technicians that all other possibilities and scenarios to correct the situation have been exhausted.
- High back seats are mandatory.
- Front windshield protection is mandatory. It is suggested to be a minimum .090” screening.
- Kill switch within reach of driver is mandatory.
- 10″ minimum vertical opening on right side of cockpit is mandatory.
- Driver side window net is mandatory. (must be closed while on track)
- Minimum 3 inch wide seat belts, mounted to frame with bolts or looped over frame tubes, belts traveling through bottom of seat are mandatory and minimum 3 inch wide shoulder harness double over shoulder, military shoulder straps with anti-sub crotch belts, harness to go over a horizontal tube located no less than 3 inches below the top of the driver’s shoulders are mandatory. All belts must be less than 5 years old.
Other Suggested Safety Equipment:
- Knee pads or padding around steering.
- Flame retardant underwear.
- Flame retardant head sock
- Flame retardant foot socks.
- Neck collars.
- Headrest padding.
- Right side head net or support with quick release capabilities.
- Arm restraints.
- Head and Neck Restraint System (HANS, Hutchens, D-Cell or other brand)
- Securely mounted fire extinguisher within reach of driver.
Fuel Cell/Trunk Area:
- Fuel cell is mandatory and must be securely fastened with at least two (2) one inch straps inside the trunk.
- Fuel cell placement must be between frame rails.
- Fuel cells may not sit lower than the rear end.
- Rear of fuel cell must be protected with hoop under and above rear bumper.
- Fuel cell vent hose MUST extend equal to or lower than bottom of fuel cell.
- The battery may be relocated but must be securely fastened and have a protective covering regardless of location.
- No batteries are to be located in the driver’s compartment.
Note – these rules are subject to change during the racing season. The officials’ interpretation of these rules is FINAL. Variations from any specification or rule must be approved by the speedway tech officials. All cars are subject to technical inspection at any time. Refusal to allow technical inspection may result in disqualification and loss of points and prize money for that event.