Hobby Stock

Welcome to Chowchilla Speedway! Throughout 2020, we are hosting numerous Hobby Stock races in Central California at the Chowchilla Speedway. If you wish to compete, then you must comply with the following rules. If there is no rule saying you can change it, then you must leave the part stock. As always, we are happy to answer any questions you may have. We look forward to seeing you and your vehicle on the raceway!


  1. 1960 or newer American made 2 or 4 door.
  2. 2 wheel drive only.
  3. 96 inch minimum Wheelbase.
  4. Cars only.


  1. Body and frame must match make and model.
  2. Car must remain stock appearing.
  3. All glass, chrome, and flammable materials from inside and outside of car must be removed.
  4. No hood scoops or spoilers allowed.
  5. Trunk may be cut out large enough for fuel cell, must be blocked back in.
  6. Front inner wheel wells may be removed.
  7. Dash may be removed and replaced with fabricated dash.
  8. Fenders may be cut 3-inches around the tire for clearance.
  9. All doors must be welded shut.
  10. No excessive gutting allowed.


  1. Must use stock appearing bumpers.
  2. Bumpers must be mounted in stock location.
  3. Must have safety chains and tow straps.
  4. Bumpers must be attached to fenders.


  1. All seats must be a padded aluminum-racing seat.
  2. Seats must be securely mounted to roll cage.
  3. Seat belts must be racing type 3 inch.
  4. All belts must be kept in good condition.
  5. Seat belts must be bolted to roll cage with no less than 5/16 aircraft bolts.


  1. All cars must use matching stock springs. May cut for ride height.
  2. No racing shocks allowed.
  3. Stock wheelbase for year, make and model, maximum one inch. difference.
  4. No tying frame rail front to back.


  1. No locked, posi or limited slip rear ends allowed. Can not lock up at any rpm.
  2. No shimming as to make a locked rear end.
  3. Must use stock o.e.m rear end. (Ford to Ford & Chevy to Chevy)
  4. No floaters, quick change (etc.)
  5. Driveline must be painted white.
  6. Driveline must have two safety loops, one in front and one in back.


  1. Stock intakes only.
  2. Cast iron only.
  3. No high risers of any kind.
  4. No modifications allowed.


  1. Stock exhaust manifolds only.
  2. No headers.
  3. Center dumps are okay.
  4. Must run a muffler not to exceed 95 db. at 100 feet.
  5. No exhaust of any kind inside of car.
  6. All exhaust must extend pass drivers seat.
  7. Exhaust must have straps or chains front and rear.
  8. Exhaust no larger than 2 ½ inches.
  9. Duel exhaust is okay.


  1. Must run stock ignition.
  2. H.E.I. is okay.
  3. Battery may be relocated in trunk area or behind driver.
  4. Battery must be in container and securely mounted.
  5. Ignition and battery must have a on and off switch painted in either red or yellow. Mounted to the left of the driver, and must be able to reach from outside of car.


  1. All numbers must 20 inches tall and 4 inches wide.
  2. All cars must have a number on both sides and roof.
  3. Use colors that score keepers can read.


  1. No electric fuel pumps.
  2. Any fuel line running through drivers compartment must be in a steel sleeve.
  3. All cars must have fuel cell.
  4. Cells must be sealed in steel container.
  5. Must have roll over valve.
  6. Cells may not be any lower than middle of third member.
  7. Must use gas only. (Racing gas ok)


  1. Maximum 7 inch. Steel rims are mandatory, but it can have any offset. 
  2. Maximum 71/2-inch street tire 13-14 or 15 inch.
  3. No mud or knobby tires allowed.
  4. Diamond back re-treads 225-70-15 okay. 

If 71/2 or less

  1. All tires must be same size. (13-14-15)
  2. 1-inch lug nuts mandatory.
  3. If using stock rims the center must be reinforced.


  1. All engines internally and externally must remain stock per year make and     model, unless listed below.
  2. RV cam max lift .458.
  3. Maximum 180lbs of compression any time.
  4. No less than 16 inches of vacuum at 800 rpms checked at or by carb.
  5. No double hump heads.
  6. May interchange heads. (305 to 350-350 to 305)
  7. Dish or flat top pistons only.
  8. Aftermarket flat top pistons ok.
  9. Aluminum Radiators allowed.


  1. Holley 4412 or Rochester 2-G. Must remain stock. ( may change jets)
  2. 1-inch spacer allowed.
  3. Must replace throttle cable with metal rod.


  1. Must use stock clutch and transmission.
  2. All transmissions must have explosion proof bell housing or shield.


  1. Must have 4 stock working brakes.
  2. No proportioning valves of any kind.


  1. No quickeners.
  2. May change steering column.


  1. Full roll cage is mandatory.
  2. .095 or heavier seamless.
  3. Gussets required on all 90 deg. Joints.
  4. Minimum of 4 door bars on driver’s side.
  5. Roll cage may extend up to the front of the frame horns for radiator support and to rear of car inside body.
  6. All bars close to driver must be padded.


  1. Neck braces and gloves recommended.
  2. Nomex-type racing fire suit mandatory.
  3. Fire extinguisher securely mounted in car.
  4. Full faced helmet SA-1990-95 in good shape.
  5. Driver’s side window net mandatory.