Pro Stock Division 


The rules and/or regulations set forth herein are designed to provide for the orderly conduct  of racing events and to establish minimum acceptable requirements for such events. These  rules shall govern the condition of all events, and by participating in these events, all  participants are deemed to have complied with these rules. NO EXPRESSED OR IMPLIED  WARRANTY OF SAFETY SHALL RESULT FROM PUBLICATIONS OF OR  

COMPLIANCE WITH THESE RULES AND OR REGULATIONS. They are intended as a  guide for the conduct of the sport and are in no way a guarantee against injury or death to a  participant, spectator, or official. 

The race director shall be empowered to permit reasonable and appropriate deviation from  any of the specifications herein or impose any further restrictions that in his/her opinion  does not alter the minimum acceptable requirements. NO EXPRESSED OR IMPLIED  WARRANTY OF SAFETY SHALL RESULT FROM SUCH ALTERATION OF  SPECIFICATIONS. Any interpretation or deviation of these rules is left to the discretion of  the officials. Their decision is final. 

• The Management of Clinton County Fair and Speedway. 


• Any North American made car 1968 to present. No jeeps, station wagons, compact cars, trucks, four- wheel drive vehicles, convertibles, or Corvettes. 


• 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 rearview mirrors of any type. 


• Frames MUST remain STOCK APPEARING. 

• There must be a significant portion of a stock factory front clip, must include main frame rails  and crossmember with factory lower control arm mounts in stock location. The clip may be  altered to allow for clearance issues of items such as the oil pan and fuel pump. Any clips which  speedway officials have deemed to have been extremely or excessively altered may be required  to add weight to the front of their car. Aftermarket and full fabricated front clips are not  permitted.  

• 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 bracingallowed 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. 


Front Suspension: 

• 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. 

Rear Suspension: 

• 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. • Leaf spring slider mounts are 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. 

• 4 link cars the rear- coil springs cannot be any greater than 16 inches. 

• Lower spring plates must remain stock and unaltered. 

• 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 independent rear suspensions. 

• All springs and spring pockets must remain in stock location. 

• Leaf springs only, must be stock appearing and full length. 

• Adjustable lowering blocks permitted with leaf springs 

• Slider blocks are permitted with leaf springs 


• 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. 


• 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. • All rods must have stock dimension size on both ends. 

• 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. 

• Stock location coil. 

• 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: 

se 103 Measurement 81″
104 82″
105 83″
106 84″
107 85″
108 86″


• 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 


– maximum wheelbase on right side is 105” 

– minimum wheelbase on right side is 103” 

Rear Ends

• 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. 

• Adjustable lowering blocks permitted with leaf springs 

• Slider blocks are permitted with leaf springs 


• Stock transmission or stock style replacement. 

• 1:1 late model style transmission is permitted, (BERT, BRINN, FALCON,Etc.). No ball spline or  roller-slide transmissions. If using a 1:1 late model style transmission, must add minimum of  25lbs forward of the centerline of the rear of the transmission. And 25lbs forward of the rear of  the bellhousing.  

• 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. 

• 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.

• Automatic transmission with a working torque converter is permitted. 

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. 

• Boxing driver’s compartment is permitted. 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  ofright 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 MUSThave a  Camaro shaped body etc. 

• 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. 

• No wings or 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. 

• Spoilers are not permitted. 

• 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) are 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 or plastic, NO Late Model style elephant ears, MD3 or other down force types  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
97 Firebird
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
Olds Cutlass
Buick Regal

Body – Sail Panels: 

• Must resemble size and shape of factory OEM panels. 

• Sail panels must be flat front to back and top to bottom. 

• Rear of panel must line up with the 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. 

• 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 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. Failure to do  so will result in disqualification and will be 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. 


• 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 parts  supplier. 

• 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 devices 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. 

Safety Equipment: 

• High back seats are mandatory. 

• Front windshield protection is mandatory. It is suggested to be a minimum .090” screening. • 10″ minimum vertical opening on right side of cockpit is mandatory. 

• Driver-side window net required, minimum 16 inch by 20 inch ribbon or mesh style and must be  mounted to roll cage so latch is at top front of window.  

Maximum four inch tall visor attached to window net.  

• Minimum 3 inch wide seat belts,SFI-Approved five point safety belt assembly required. Must  be 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. Recommended: Safety  belts no more than two years old.  

• Racing (not motorcycle) helmet required, Snell-rated SA2010, SA2015 or SA2020 helmet  required. 

• Recommended: Fire retardant padding.  

• SFI-approved full fire suit required.  

• Fire retardant gloves, shoes, and neck brace (or head and neck restraint) required.  • Right and left seat head supports required if using head and neck restraint system.  • Recommended: Fire retardant head sock and underwear.  

• Master kill/fuel pump switch required on left side of dash within easy reach of driver and must be  clearly marked ‘OFF’ and ‘ON’.  

• A fire extinguisher (5 lb. minimum) is recommended Must be mounted securely within drivers  reach 

• Recommended use of Neck collars or Head and Neck Restraint System such as HANS. • Recommended headrest padding and arm restraints. 

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. 

• One 12 volt battery per car 

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. 

Revised 1/2022