NEWPORT Speedway Street Stock Rulebook DIRECTORY
  1. Competing Models
  2. Body
  3. Weight
  4. Engine
  5. Head
  6. Intake and Spacer
  7. Carburetor
  8. Air Cleaner
  9. Cooling System
  10. Exhaust
  11. Transmission and Flywheel
  12. Rear End
  13. Springs and Shocks
  14. Frame
  15. Wheels
  16. Tires
  17. Fuel and Fuel System
  18. Electrical System
  19. Brakes
  20. Roll Cage
  21. Spoiler
  22. Bumper
  23. Wheelbase
  24. Tread Width
  25. Safety
  26. Numbers

  1. COMPETING MODELS:
    1960-1990 models only of American rear wheel drive cars with a minimum wheelbase of 106" Wheelbase must be for make and model of car and remain unaltered.
  2. CAR BODIES:
    1. Body must remain stock.
    2. NO hulling or reinforcements permitted with the exception of the hood, front fender wells and trunk lid. All must remain stock.
    3. Anything that bolts in may be removed.
    4. All panels must remain stock except hood.
    5. Firewalls must remain in stock location and be minimum 22 gauge steel.
    6. Hood may be fiberglass and must have 5 hood pins total; 3 across the front.
    7. All hood and cowl air vents must be removed or covered.
    8. Hulling for door bars is permitted.
    9. Doors must be welded shut.
    10. All glass and flammable materials must be removed.
    11. Windshield required; back glass optional; 1/8-inch Lexan required.
    12. Quarter panels and front fenders may be cut for tire clearance only.
    13. Front inner fenders may be removed.
    14. Pre-fabricated magnetic steel after market bodies (body kits) allowed per track approval: - NO ARP, FiveStar, Hooters ProCup, etc. Super Late Model or Late Model Stock style/type bodies; - cars must maintain a Street Stock, not a Late Model appearance.
    15. Any fabricated sheet metal must be minimum 22 gauge steel.
    16. Chassis height minimum 5 inches, roof height minimum 49-inches.
  3. WEIGHT:
    1. Cars with screw jacks or adjustable shackles: - 3200 pounds with driver before and after race. Only gas and water may be added after race; - 1450 pounds minimum right side weight before and after race.
    2. Cars without screwjacks or adjustable shackles: - 3100 pounds with driver before and after race. Only gas and water may be added after race; - 1400 pounds minimum right side weight before and after race
    3. All weight must be painted white with car number clearly identified upon it: - added weight must be in block form, weigh no less than five (5) pounds and be securely bolted in place; - no weight may be added outside of the frame rails, ahead of the front spindles, or behind the rear axle.
    4. Any car competing with dislodged or lost weight may not add it back to make weight requirements after the race.
  4. ENGINE:
    1. Only standard production engines allowed. Chevrolet 350 cubic inch maximum, Ford 351 cubic inch, Chrysler 360 cubic inch.
    2. Engines may be interchanged in manufacturer lines only.
    3. Engine may be balanced.
    4. Steel racing oil pan permitted.
    5. No windage trays in oil pan.
    6. No polishing or painting inside of block.
    7. Overbore of .060 permitted.
    8. No electric fuel pumps permitted.
    9. Stock connecting rods only. No polishing or machine work will be permitted.
    10. Flat top or dish pistons permitted. Stock replacement only. Pistons must have "four eyebrows" all the same size; and weigh a minimum of 600 grams.
    11. Stock crank with stock stroke must be retained. Crank casting number must not be removed. Steel crank minimum weight 48 pounds, cast crank minimum weight 50 pounds.
    12. Crank journals may be ground for undersize bearings. No other machine work will be permitted.
    13. Piston must not extend above top of block. Except Chrysler.
    14. Four bolt-main blocks permitted with stock caps only.
    15. Stock water pumps only. No aluminum pumps will be permitted.
    16. Aluminum and aftermarket pulleys allowed.
  5. HEADS:
    1. Stock production steel heads only.
    2. No vortec heads, no angle plug heads
    3. NO modifications, no porting or polishing. No grinding of any kind. 3 angle valve job ok as per Late Model Stock rule.
    4. 72cc minimum.
    5. Maximum valve size 1.94-inchintake and 1.50-inch exhaust.
    6. Stock hydraulic cam and lifters with a maximum lift of .450-inch and stock rocker arm ratio. Lift will be measured at the retainer after replacing the hydraulic lifter with a solid lifter.
  6. INTAKE and SPACER:
    1. Only the following Edelbrock aluminum intakes are permitted. Chevrolet #2101, Ford with 4bbl heads #2665, Ford with 2bbl heads #2750, Ford Windsor #2181, Chrysler #2176; - any stock cast iron single plane intake manifold allowed.
    2. No porting, polishing or gasket matching will be permitted.
    3. Only a one-piece solid aluminum spacer, ¾-inch thickness may be installed between intake manifold and carburetor.
    4. Spacer must be centered on intake manifold.
    5. Spacer must have 2 holes with 1 ½-inch openings that match the base of the carburetor. Holes must be centered and cut perpendicular with the base of the carburetor. No tapers or bevels.
    6. Only 2 paper gaskets, 1 per side, maximum thickness .065-inch will be permitted.
    7. No adjustable spacer will be permitted.
    8. No other modifications will be permitted.
  7. CARBURETOR:
      Holley 2300 2bbl carburetor model #7448 with a venturi size of 1 3/16-inch and maintaining throttle bore maximum size of 1 ½-inch. See below for rework guidelines:
    1. No polishing, grinding or drilling holes will be permitted in the body of the carburetor.
    2. Choke may be removed and all holes must be permanently sealed.
    3. Choke horn may not be removed and/or altered.
    4. Boosters may not be altered in any manner including size, shape or height.
    5. Venturi area must not be altered in any manner. Casting ring must not be removed.
    6. Base plate must not be altered in shape or size.
    7. Stock butterflies must not be thinned or tapered. Idle holes may be drilled in butterflies. Screw ends may be cut even with shafts, but screw heads must remain standard.
    8. Throttle shafts must remain standard and must not be cut or thinned in any manner.
    9. Any attempt to pull outside air other than through the venturi is not permitted.
  8. AIR CLEANER:
    1. Round air cleaner element minimum of 12-inches; maximum of 17-inches in diameter permitted.
    2. Top and bottom of air cleaner must be the same size.
    3. Element must be minimum of 1 ½-inch and a maximum of 4 inches in height.
    4. Dry type paper element only.
    5. No tubes, funnels or anything which may control the flow of air are permitted inside the air cleaner or between the carburetor and air cleaner.
    6. No shield around air cleaner will be permitted.
    7. Base of air cleaner cannot extend higher than carburetor choke horn.
  9. COOLING SYSTEM:
    1. Aluminum radiators permitted.
    2. All cars must have catch can mounted under hood or trunk.
    3. Antifreeze is not permitted.
    4. Electric fans are permitted.
    5. Radiators must be stock appearing and installed in front of the engine.
    6. Track officials must approve all radiator ductwork.
  10. EXHAUST:
      Single flange tube headers permitted. Maximum ID 1 5/8-inch.
    1. No wrap around or 180 degree headers will be permitted.
    2. OEM stock cast iron manifolds permitted.
    3. Aftermarket exhaust manifolds permitted.
    4. Exhaust collectors and exit pipes must not exceed 3" OD.
    5. All exhaust must exit under the car and behind the driver.
    6. No thermal wrap will be permitted on headers, collectors or exit pipes.
  11. TRANSMISSION and FLYWHEEL ASSEMBLY:
    1. Automatic, 3 or 4 speed transmissions permitted. All forward and reverse gears must be in working order from driver's seat in car.
    2. Automatics must have stock torque converter.
    3. No aftermarket transmissions will be permitted.
    4. All clutches and pressure plates must remain stock. All flywheels must weigh a minimum of 20 pounds.
    5. Clutch minimum size 10 ½-inches.
    6. Blow proof bell housing permitted.
    7. If stock bell housing is used a scatter shield or some type of belted material must be installed to the floor pan.
    8. Hydraulic clutch slave system may be used to operate clutch.
    9. Drive shaft must be at least 2 ¾-inch in diameter and be of magnetic steel only. Drive shaft must be painted white with two safety loops attached to the bottom of car.
  12. REAR END:
    1. Stock rear end for make and model of car. 10 and 12 bolt rear ends allowed. Ford 9-inch allowed.
    2. Differentials may be locked, Detroit locker or limited slip. NO Gleasons.
    3. No floating rear ends permitted.
    4. GM Metric Cars may have adjustable coil spring spacers IN REAR ONLY.
    5. Leaf Spring cars may have adjustable spring shackles in rear.
    6. Rear end hook up must be stock from factory. Trailing arms must be stock for make and model.
    7. Bolt pattern: 5” X 4 ½”, 5” X 4 ¾, 5” X 5”, and 5” X 5 ½”.
    8. No cambered rear ends.
  13. SPRINGS and SHOCKS:
    1. Heavy duty springs optional as long as they fit in original position. No coating permitted.
    2. Any approved steel non-rebuildable, non-adjustable shock that bolts in stock position allowed. Shocks must be approved by track officials.
    3. May be shortened to lower car.
    4. Up to 3-inch lowering blocks permitted on rear.
    5. Only rubber type spacers are permitted in coil springs.
    6. . Springs front and rear must match body.
  14. FRAME:
    1. No shortening or altering in any way.
    2. Frame rails and sub-frames must be stock for make and year model.
    3. No interchanging of frames.
    4. Stock upper and lower A-arms must remain unaltered.
    5. Engine must remain in stock location.
    6. Solid engine and transmission mounts are permitted.
    7. Stock spindles, steering box and steering arms only.
    8. “X” may be added between the inside of the frame rails for driver protection.
  15. WHEELS:
    1. Maximum width 8-inches.
    2. Steel wheels only.
    3. Air bleeders will not be permitted.
    4. Racing wheels with any offset on all 4 wheels permitted.
    5. All 4 wheels must be the same size.
    6. At least 3 threads must be visible outside the lug nut on all wheel studs.
    7. No modifications/repair of steel wheels allowed.
  16. TIRES:
    880 treaded Hoosiers
  17. FUEL and FUEL SYSTEM:
    1. Track fuel only
    2. No mixtures of any kind.
    3. No nitrous oxide permitted.
    4. Cooling of fuel not permitted.
    5. Fuel cells are mandatory.
    6. The maximum capacity allowed is 22 gallons
    7. Fuel cells must have working check valve and foam.
    8. Fuel cells must be mounted equal distance between frame rails and have 9-inch minimum ground clearance.
    9. Fuel cell must be mounted in approved steel can.
    10. Right side fuel fill not permitted.
    11. Electric fuel pump not permitted.
    12. A fuel cell protector bar must be installed at the rear of the frame.
  18. ELECTRICAL SYSTEM:
    1. OEM starter only and must be in working order.
    2. Battery may be relocated but must be bolted down securely and covered or placed in a battery box.
    3. Only one 12-volt battery permitted.
    4. Stock HEI ignition permitted.
    5. Stock distributor with single point permitted.
    6. No dual point distributor permitted.
    7. No racing coils permitted.
    8. No aftermarket distributors permitted. NO MSD boxes.
    9. Distributor must not be modified in any way. 10. No ignition boosters permitted.
  19. BRAKES:
    1. Stock brakes. No dual master cylinders.
    2. Stock brake and clutch pedals.
    3. Disc brakes permitted on all wheels.
    4. One master cylinder with no proportioning valves permitted.
  20. ROLL CAGE:
    1. 4 point cage with curved door bars required.
    2. Roll bars must be welded and made of at least .090 roll bar tubing.
    3. Approved loop around radiator and behind grille is permitted.
    4. Roll bars may be extended through engine compartment and rear deck.
  21. SPOILER:
    1. Homemade spoilers must not be over 5-inches high and must be no wider than the deck lid.
    2. Spoiler must be mounted on the rear of deck lid.
    3. Factory spoilers permitted on rear.
    4. No front spoilers of any type
    5. Homemade spoilers must maintain a 40-50 degree angle.
  22. BUMPER:
    1. Bumpers must be stock appearing for make and model.
    2. ABS tail and nose cover allowed. Support bars behind nose maximum size is 1-¾ inch round or 2-inch square. 2 bars maximum.
  23. WHEELBASE:
    Wheelbase must be stock from factory.
  24. TREAD WIDTH:
    Steel or billet stock aluminum spacers maximum of ½-inch thick per wheel will be permitted to utilize the maximum allowable tread width. Spacers, if used, must be the same thickness left and right; however, the front and rear do not have to agree. Cars must not exceed the maximum allowable tread width of 65 ½-inches, front and rear measured from the inside of one wheel to the outside of the other wheel, zero toe in, at spindle height. A tolerance of ½-inch will be permitted between the front tread width and rear tread width, but the widest tread width must not exceed 65-½ inches. No welding allowed on any wheels.
  25. SAFETY:
    1. Aluminum race seats required
    2. 5 or 6 point race harness required
    3. Seat belts must have manufacture date within 3 years date of event
    4. Inside mirror permitted
    5. Functional driver's side window net required
    6. Car must be equipped with on-board fire extinguisher
    7. Helmets required
      - must meet SA95 or SA2000 requirements
      - drivers SFI suit requiredMbr>
    8. Driveshaft safety loop required
  26. CAR NUMBERS:
    1. Car numbers must be visible for scoring purposes
    2. Door numbers must be 18-inches in height
    3. Posted on both doors
    4. Roof numbers required
      - 28-inch minimum height
    5. recommended to face reading toward tower/grandstand
    NO RADIOS!!!
    Track officials will have discretion to modify these rules as needed including event night changes.
    Track officials will determine legality of all components.