Afton Motorsports Park Street Stock Class Rules

The Street Stock class rules for Afton Motorsports Park are listed on this and four other pages, linked to below.


Page 1 of Rules: [Go to page 1] Includes Eligibility Requirements, Former Prostock/Super Stocks, Bodies and Aluminum Body Rules.
Page 2 of Rules: [Seats/Interior] [Roll Cage] [Suspension]
Page 3 of Rules: [Go to Page 3] Includes Drivetrain, Weight, Wheels and Tires, Brakes, Shocks, Transmission, and Engine.
Page 4 of Rules: [Go to page 4] (Engine continued) Includes Vortec Head and Intake Heads, Headers, Intake, Ignition, Cooling System, Fuel Systems, Carburetor, Option 602 Street Stock Engine
Page 5 of Rules: [Go to page 5] Includes Body Installation Guidelines Diagram.

[PDF of Street Stock Rules] [Download Adobe Acrobat]

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  1. Aluminum Seat is mandatory, minimum .095" material.
  2. No fiberglass, bucket seats, or factory original car seats.
  3. Seat must be mounted no further back than 32" from center of rear housing, measured from rear end to bottom of seat back.
  4. A 1" inspection hole must be provided in rear firewall at center of seat back bottom location.
  5. Driver must be protected by a sealed front and rear firewall.
  6. Stock firewalls may be replaced with 20 gauge steel or .080" aluminum.
  7. Rear window shelf must be completely sealed across entire window base to rear firewall.
  8. No sharp edges.
  9. Steering column must be aftermarket, but must remain in original location.
  10. Aftermarket gas pedals recommended must have toe lift loop.
  11. No cable operated throttles allowed.
  12. All pedals must be in stock location in driver's compartment.


  1. Complete six point cage with at least main cage a mandatory of 1.5 x 1/8" wall tubing minimum, no black iron pipe. All junctions not meeting safety standards may be required to be gusseted. Minimum of one 1" vertical bar down center of windshield area with entire windshield area covered with 1/2" square steel screen.
  2. All cages will be centered on chassis, no LM offsets or severely setback cages.
  3. Right side of main cage must be welded down to original frame rail even if an inboard straight rail has been added inside the OEM frame. Cars with main hoop mounted to inboard frame rail section must either add 150 pounds to the middle of the OEM right side frame rail or add auxiliary uprights and X frame door bars up to the height of the door and tie them into the main uprights.
  4. All cages must have a minimum of 3 door bars on each side with 4 recommended on driver's side. When only 3 are used on driver's side, there must be sufficient verticals tying them together with gussets.
  5. Lowest bar cannot be lower than driver's hip area in seat and top bar must come sufficiently high enough to protect driver's shoulder area.
  6. OEM door pillars and rocker panels can be removed but must be replaced with vertical bars tying door bars to main cage, and rockers must be replaced with crush panels that seal off driver's compartment.
  7. Nerf bars are optional between front and rear tires, but must be tight to door panel, with no sharp edges, and have ends turned inward. Must be securely fastened in at least 2 places to cage and not just to body panels. Nerf bars allowed behind rear tires tying into bumper ends, and must be fastened to frame inside rear fender. Same procedure applies for front corner nerf bars.
  8. All nerf bar material must be a maximum of 1.5" OD tubing or square stock.
  9. Rusted rear frame sections may be replaced by tubular or square steel anywhere behind rear most suspension mounting point to rear bumper area.
  10. No collapsible OEM bumper shocks.
  11. All bumpers and bumper support bars must be securely bolted and or welded to frame.
  12. All Uni-bodies cars must have sub-frame sections welded in place with both front and rear clips remaining in stock locations and configuration, including strut cars.
  13. Bumpers must be securely mounted to frame, with ends enclosed or protected, with a minimum of a loop bar in the center or heavy chain loop for wrecker use.
  14. No cowcatcher types bumpers, or severely over built bumpers allowed.
  15. Minimum of 1.5" diameter bumper support bar, not to exceed 4" diameter tubing behind stock type bumpers or nose pieces.
  16. All interior roll bars within reach of driver will be padded with rollbar padding.
  17. No pipe insulation.
  18. Window net is mandatory.
  19. No old string type nets allowed.
  20. TOW HOOKS: Must have tow hooks on front and back, hooks must be easily accessible by tow truck operators without removing hood.
  21. Driver must be able to open window net while fastened in car.

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  1. All suspension components must be stock and used in stock locations for make of car.
  2. Full frame cars can have rear frame from center of rear axle back replaced with 2x3 tubing.
  3. Unibody cars can have the frame replaced with 2x3 tubing from 36" behind centerline of front wheels. 2x3 tubing must go over the rear end housing.
  4. Front frame on all cars can be replaced forward of the steering box and idler arm only (front steer cars) with tubing.
  5. Aftermarket racing springs allowed but no coil over or coil springs sliders /eliminators, torque arms, or other aftermarket racing suspension components.
  6. Front and rear jacking bolts allowed. Weight of all cars 3000 LBS.
  7. No drop spindles or aftermarket hubs, or tie rods etc. OEM only.
  8. Non stock or aftermarket ball joints and tie rod adjusters allowed. May use aftermarket adjusting sleeve, maximum 4 ½ inch length.
  9. A frames OEM stock.
  10. Upper A frames may be replaced with a steel shaft tubular A frame. Aftermarket upper A frame mounts allowed in OEM location with a max. 1 inch tolerance. Control arm length of 9 inches MAX. Strut cars can run auxiliary shocks but must disable dampening of original strut shock by drilling and draining fluid.
  11. No heim joints used on control arms, tie rods or sway bars. Spindle saver bolt on braces allowed on metric spindles. No Ford or Mopar suspension parts on GM vehicles. No rear swaybars unless factory installed.

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