2018 Hobby Stock Rules




OEM is the abbreviation for original equipment manufacturer. No carbon fiber parts anywhere on the car.


  1. 1965 or later American mfg. stock production sedan with steel top. 2 door or 4 door, No front wheel drive. Body does not have to match the manufacturer chassis.
  2. Wheelbase stock for year, make and model. 104” minimum to 116” maximum +/- 1” for year make and model.
  3. Minimum weight for car with driver 3,300 lbs. Any car found to be under the minimum weight requirement will be penalized one (1) position per pound overweight.



  1. Must be mfg. stock for year model used. Fenders, doors and rear quarter panels may be interchanged with similar models as long as end result looks stock. Any fabricated body part must be 22-gauge steel or aluminum.
  2. No cutting away of exterior sheet metal except as outlined:

a.) Body sheet metal may be trimmed for tire clearance a  maximum of 5″ above tire on both sides of car in race ready           position.

b.) Rear trunk floor and outer portion of inner fender panels  may be removed. Inner body panels may be removed.

c.) All glass and chrome trim must be removed.

d.) Windshields must be replaced with maximum ½” wire mesh and must have one (1) center vertical support of minimum 1” x 1/8” steel strap.

  1. Air cleaners must be sealed. No air scoops on the hood. Hood and deck lid must have approved quick pull positive hold pins.
  2.  No fiberglass or plastic fenders, trunk lids or quarter panels may be utilized. Fiberglass hoods OK. Any nose piece may be used, MD3 OK, must look stock, no late model noses or MD3 Late model noses.
  3. Engine to driver’s compartment must be completely sealed. Driver to trunk area must be completely sealed.
  4. 6” rear spoiler allowed. No wider than the stock trunk unless using a OME spoiler.
  5. Body side skirts allowed. Doors and Quarters must be rolled or creased to match front fenders
  6. Stock or full manufactured sealed floor pan and fire wall.
  7. No glass windshields allowed. Must have center supports.
  8. Body manufacturers may be interchanged per manufacuter chassis, wheel base must remain stock for chassis being used. (examples Ford body may be used on Chevy chassis, Monte Carlo body may be used on Camaro chassis)
  9. Number must be on both sides of car located on door. Must also have number located on roof and on front of car located in approximate headlight area and taillight area. Minimum number size is 20″. Number lines must be a minimum of 4″ and in contrasting color to the body of car.
  10. 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. Strict enforcement on secure mounting. No zip ties or pop riveting. Hard mount only.
  11. No mirrors of any kind allowed.
  12. No 2 way radios allowed. RACECIEVERS MANTORY.
  13. Must run AMB transponders mounted on the right side of the car right side at firewall.


A. Engine Blocks:

1.Stock OEM engine blocks only. No aluminum. Ford, Chevy 360 CUBIC INCH MAX no Chevy 400 blocks. Chrysler 370ci. Studded main caps allowed. Must have stock casting numbers on block. of the car Blocks must not altered in any way so that it could not be used in a street legal production car. Chevy Crate 602 are OK, must have hydraulic cam and stock rockers, 602 motors without seals must conform to the open motor rules, NO 604 crate motors, No 604 blocks or heads to be used in open motors

  1. After market pulleys and air cleaners, valve covers allowed.
  2. After market fans allowed.

4. Aluminum water pumps OK.

B. Pistons:

  1. Flat top pistons ONLY. No lighting of any kind. No domed pistons allowed. Pistons are no touch.

C. Heads:

  1. Stock OEM or World Products S/R Torquer Cylinder Heads for Chevrolet part# 4266 and 4267 or part #5303 for Ford. Dart heads, part #10024361 and Speedway part #9154622 for Chevy.
  2. No aluminum, angle plug, or aftermarket racing heads allowed, except for the above listed.
  3. No port matching, no pocket porting or blending. No angle plug heads.
  4. Stock appearing stamped steel rockers only. Roller tips OK, No alloy, no chromolly or titanium allowed. No rollers. Screw in studs OK. Large valve springs OK. Guide plates OK.

D. Camshaft:

  1. Any hydraulic or solid lift cam. Vortex heads and all 602 must  run hydraulic cam.
  2. No roller or mushroom cams allowed. No gear drives allowed. 

E. Intake and Carburator:

  1. Stock OEM 2 barrel cast iron intake manifold only. No modifications. No Hi –rise intakes.
  2. Edelbrock Torker II.
  3. Edelbrock Performer, Chevy part #2701 or Ford part#71221
  4. Weiland, Chevy part# 7547 or Ford part# 7515
  5. Carburetor spacer must not exceed 1″ max. No funneling of  spacers.
  6. One Holley #4412 500 cfm carb allowed. May remove choke plate and change jetting.
  7. Gasoline only. No alcohol. No mixing of fuel.

No porting or polishing of any kind to any intake. Intake manifolds are a no touch item.

F. Additional Rules:

  1. Exhaust pipes must extend to the rear of the driver and point to the outside of the car. Stock cast exhaust only, center dumps are allowed. 2. No high performance manifolds or headers allowed. No Brzezinski manifolds may be utilized. No modification of any kind allowed to exhaust manifolds.
  2. Mufflers mandatory. Maximum DB reading 80 decibels at 100 feet. Mufflers and tail pipes must be mounted below or underneath stock floor pan. No part of the exhaust system is allowed inside the driver’s compartment.
  3. No electric fuel pumps allowed. Fuel cells mandatory. Fuel tank must be retained by minimum of four (4) straps; two (2) crossways, two (2) lengthwise.
  4. OME Automatic stock transmissions. Must be equipped with one stock working torque converter , 11 inch diameter minimum width. No stall converter. 3 or 4 speed manual transmissions allowed. All gears must work at all times. Transmission cooler OK must be located in the trunk of car.
  5. Single type clutches only. No triple disc.
  6. No aluminum flywheels. Flywheel must be O.E.M. No aftermarket flywheels.
  1. Aftermarket power steering pumps OK.
  2. No air forced boxes allowed.
  3. Engine must be mounted in stock location.
  4. A quick release steering wheel may be used. Must be padded. Steering quickner allowed. Stock steering columns may be removed and replaced with aftermarket steering shaft u-joints and couplers.
  5. Drivelines must have two (2) retaining straps, one (1) near the front and one (1) near the back. May be made of chain or metal strap. Drivelines must be painted white. No aluminum drivelines.
  6. O.E.M. 4 wheel brakes in good working order required. No turning brakes of any kind allowed.
  7. No dual racing type master cylinders or balance bars allowed.
  8. One brake master cylinders ONLY may be mounted any location.
  9. Distributors must be stock point or HEI type. No racing modules or coils allowed. No MSD or Mallory modules allowed. MSD or Mallory wires OK. One 12volt battery only. No double coils. No electronic ignition unless stock for make and model. MSD wires OK.
  10. All cars must be equipped with one working starter mounted in stock location. Mini starters allowed.



A full perimeter roll cage is required. No offset cage allowed. There must be a minimum of four (4) driver side bars in the left door area. Two (2) bars must extend from the top of roll cage to the rear of the frame rails. One (1) bar must extend from the left side to right side of rear roll cage at floor pan level for seat belt attachment. One (1) diagonal bar is required across the rear of roll cage from top to bottom. One (1) bar must be installed from left side of roll bar to center part of cross bar at shoulder level for shoulder harness attachment. Additional roll bars may be added. Where roll bars are attached to the floor pan, must have steel mounting plates under and over floor pan.

Plates must be a minimum of 4″ x 6″ x .125 steel. Single pipe front loop may be installed at radiator top tank level.

  1. Radiator protection bar and supports may be added. Subject to technical inspection and approval. All radiator protection bars must be behind the bumper and under front nose piece. All main cage roll bar material must be a minimum of 1 3/4″ .090″ wall steel tubing No thread pipe fittings allowed. All roll cage welds must have a minimum 2″ x 11/2″ x 11/2″ x .125″ steel gussets. All roll bar structure exposed to the driver must be padded with approved padding. Roll bar construction and installation is subject to inspection and approval. No offset roll cages. 1/8″ plates on left side door bars are required this plate must cover rocker panel to the bottom of the top door bar and from the rear upright to a minimum of 12 “ in front of the leading edge of the drivers seat.
  2. Racing seat mandatory. Seat must have complete cage frame support fabricated to the roll bar assembly. No fiberglass seats.
  3. A five (5) point safety harness, with quick release mandatory with a three inch wide lap belt, 3″ shoulder belts and a 2″ submarine. All belts must be attached to roll cage.
  4. All seat belts must have date of manufacturer and must be within 3 years of the present date. It is for your safety.
  5. 5. Roll bar padding mandatory where ever the drivers head may make contact to the roll cage.
  6. Tube front bumpers OK. 1 3⁄4″ .095 maximum size tubing used. Must be turned backed and capped, must fit under nose piece. Aluminum bumper O.K. Front and rear bumpers must be mounted at approximately stock height and location. Bumper height measured from ground to centerline of bumper must be a minimum of 16″ and a maximum of 20″. Bumpers must not be narrowed. Bumpers must have a 90-degree turn on each side extending back a minimum of 4″ from front of car on front bumper.           Must extend 4″ forward from rear bumper. Bumpers must not have sharp corners or ends. Front and rear bumpers must have metal plates covering full width of bumper securing ends of bumpers to the quarter panels. Front and rear bumpers must have safety chains mounted to the frames. Bumpers are subject to tech approval, call for clarification. Bumpers cannot stick out passed bodies. No exceptions, it will be fixed. Bumpers need easily accessible tow hooks mounted.


  1. Frame must be stock only. Additional supports may be constructed to protect the uni-body. Such support bars must follow the contour of the frame and not extend beyond the inside of the wheels.
  2. Wheel base – minimum allowable 104”.
  3. OEM front and rear sub frames No cutting, sectioning or redesign of any frame or sub frame to change the stock location of any suspension component or engine placement.
  4. All components and parts must be stock. No weight jack devices of any kind allowed. Fixed spring buckets allowed on rear of coil cars only.



  1. Leaf spring cars may use stock style steel aftermarket replacement leaf springs front must mount in stock location.
  2. May use stock, urethane or aluminum bushings
  3. May replace stock spring pads on rear end with aftermarket pads. Fixed lowering blocks allowed.
  4. No adjustable spring hangers or sliders allowed.
  5. Coil spring cars may use any height coil spring with a minimum of five (5”) diameter in stock location.
  6. Adjustable or non-adjustable spacers on top of rear coil springs allowed.
  1. Upper trailing arm mounts on the top of rear end may be changed, moved or altered to allow pinion angle to be re-set in car.
  2. No pull bars.
  3. Rear shocks on ALL cars will be stock mounts, steel, non  adjustable and non rebuild able in stock location mounts.
  4. No rear sway bars allowed. If a rear sway bar was on the car as part of the OEM, it must be removed.
  5. Any crash damage repair must locate the suspension components in their original positions with a minimum of reinforcement. Front leaf spring mounts must be stock and in the stock location.
  6. 12. Ford 9” Steel floater rear axle assembly are allowed. Locked rear ends are allowed. One piece rotors only, weld on caliper mounts OK. Solid steel axles only. no aluminum housing or spools, no Detroit lockers, no Gold Tracks, no traction control devices of any kind. Steel brake rotors only, real disc brakes OK.



  1. Any height front coil spring in stock location. Stock diameter only. Spring spacers on top of springs allowed. No bite bolts.
  2. Any non-adjustable, non rebuildable steel shocks with stock mounts in stock locations permitted. Rebuildable or Adjustable shocks are not allowed.
  3. Upper A-Arms be steel tubular with steel or aluminum cross shaft using either bolt in or screw in ball joints allowed as long as they bolt up to stock location. Tubular A- Arms must be stock length for the vehicle year and model and must be the same length right and left. No helm joints or bearings allowed on a-arms.
  4. 4. Upper A-Arm mounting plates, must be in stock location.
  5. Lower A-arms must OEM in stock mounts.
  6. Lower ball joints may be stock type screw in, bolt in weld in or press in.
  1. No after market front spindles or brake rotors allowed. No modifications to spindles or rotors allowed. 


  1. Maximum contact width or tire is 7 1⁄2″. DOT approve tires only. No grooves wider than 3/8 of an inch. No aggressive patterns. (large lug or stud tires) All tires subject to tech approval.
  2. Antioch hobby stock track tire is OK 3. 7” or 8” wheels. Right rear and right front bead lock OK. Steel wheels only.
  3. No bleeders.
  4. Wheel studs may be replaced with larger studs up to 5/8 inches all wheels must be15”.


  1. Minimum weight 3,300 lbs with driver. All ballast weight added to the car must be mounted in a safe and secure manner. All ballast weight must be painted white and must have car number stamped or painted on each weight. All weight must be mounted with a minimum of two (2) 1/2″ grade 8 bolts or two (2) weight mounts.
  2. Any ballast weight dropped on the racetrack at any time is anautomatic disqualification for the remainder of that race event.


  1. Gasoline only. No alcohol or boosters of any kind allowed.
  2. All fuel lines in the cockpit must be sleeved with steel tubing.
  3. Fuel cells are mandatory. Roll over check valves on fuel cell  vents required.
  4. Radiator must be in stock locations in the stock position.  Aluminum is OK.
  5. All fuel cell filler caps will have a safety chain connected to the car.


Note: Any part within view is subject to tech at anytime.

  1. Fire extinguisher minimum 2 lbs. dry-chemical must be mounted in driver’s compartment. Must be accessible to the driver. Must have quick release mount. Must not be taped or plastic tied in. Additional fire extinguisher must be in pits at all times.
  2. Safety helmet must meet Snell 2005 testing standards, bear proper identification, and have no signs of previous damage. No open face helmets allowed. SFI-approved full fire suit required. Fire retardant gloves, shoes and neck brace (or head and neck restraint) required. Recommended: Fire retardant head sock and underwear.
  3. Neck brace required at all times. Hans recommended.
  4. Equipment will not be considered “legal” simply because it went through inspection unobserved or because a rule has not been written against it.




The rules and/or set forth herein are designed to provide for the orderly conduct of racing event 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 participates are deemed to have complied with these rules. NO EXPRESS OR IMPLIED WARRANTY OF SAFTY SHALL RESULT FROM PUBLICATION OF OR COMPLIANCE WITH THESE RULES AND/OR REGULATIONS. They 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 minor deviations from any of the specifications herein or impose any further restrictions that in his opinion do not alter the minimum acceptable requirements.

NO EXPRESSED 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. Referee’s decision is final. Just because it is not in the rules doesn’t mean it is legal.  

Ocean Speedway American Stocks, Bakersfield Speedway and Antioch Hobby Stocks will be allowed to compete at Merced Speedway under their tracks 2018 rule package.


Revised: 2-02-2018