1-25 Speedway 2017 STREET STOCK Rules


Revised 4.2.17

This publication supersedes all previous rules and rule updates.




I. No equipment on a racecar will be considered as having been approved because of having passed through inspection "unobserved". If this rulebook does not specifically state that a change, modification, or addition is legal, then a competitor must consider that change, modification, or addition as illegal. If a question arises about the legality of a change, modification or addition that is not covered in this rulebook, the question must be answered by I-25 Speedway in writing, and that decision is final.

  1. Registration: Street Stock drivers must turn in a fully paid and completed current year Registration Form with properly assigned car number and pit stall, as well as a current W-9 form prior to competing in any event. (Including but not limited to qualifying races.) Every effort will be made to assign the driver with the pit stall they requested, but I-25 Speedway reserves the right to move any car to another pit of equal construction (when permissible) at any time. Any car not in their assigned pit spot will be fined $50. There will be no duplicate numbers and/or letters used.

  2. Check Policy: A returned check fee of $50. will be payable in cash prior to competing in any event. Re-issue of lost checks will cost the driver $25.

  3. The Street Stock class is designed to offer competitive but affordable racing to entry level and veteran drivers. All cars must remain stock except as noted in the following rules. Visiting care may compete under their home track rules if the car has a current inspection sticker from their home track and is accompanied by a current copy of the track’s rules. Tech inspectors reserve the right to determine safety and competitiveness of any car.

  4. BEFORE you race, all required forms are to be filled out, NO forms, NO checks. (Racing without said forms is Forfeiture of that wks check-NO tolerence) (revised 1.29.17)



1 A steel can for fuel cell is required. It must be mounted on/at trunk floor level (Not below)with 2" x 1/8" steel straps or I" x I" square tubing cage mounted to rear down bars or rear bars. A tubular fuel cell

guard may be mounted in the trunk behind the fuel cell. The fuel cell must have a ground strap from the filler neck to the frame and a vent tube running through the trunk floor. A roll over valve must be installed in the vent line. Fuel line must be routed through passenger compartment in steel tubing, SOLID conduit or through the passenger side frame. Braided lines are optional.



2. All cars must have a perimeter-type roll cage constructed of minimum I ½" x 0.095 mild steel tubing. No galvanized or threaded pipe allowed. Main loop must be formed in one piece. Halo must be made in one piece. Cage must be welded directly to the frame on full frame cars or to 6" x 6" x 1/8" thick steel plate welded to the floor of uni-body cars. Front engine loops are optional. No suspension may be mounted to it in any way. Non-required tubes may be made of any size tubing. Any tubing around the driver must be padded with racing approved roll bar padding; No pipe insulation, rags, etc. allowed. Frames or sub-frames may not be reinforced or modified in any way except for braces under the trunk floor to help from buckling into fuel cell on rear impact. Sub-frames may be connected on uni-body cars with round or square tubing. Original front bumper brackets may be welded to the frame for safety. All cage welds must be free of slag and porosity. Any visible unsafe welds WILL fail tech.

2. 1 2Additional braces may be run from main cage through rear bulkhead to rear trunk floor to provide protection to the fuel cell.

2.2. Down bars from front of main cage to frame (behind upper control arms) optional. Only two bars per side allowed.

2.3  Doors must have three parallel door bars on driver's side, arching into the door for driver clearance, a seat back bar, a diagonal in the halo and a brace from the upper door bar to the left cage comer. The driver door bars must be plated with 1/8" steel plate.



3. A metal racing seat is required. It must be mounted with a minimum 1" round or square steel tube frame, which must be securely mounted to the roll cage and floor pan. A 5-point harness is required. It must be in good condition with no frayed or modified webbing. Harness expiration date shall not exceed three (3) years from date of manufacture. Harness must be mounted according to the manufacturer's instructions or general accepted competition guidelines.

  1. A quick release steering wheel is required. Any stock column used must have key/steering lock disabled. A fabricated steering shaft of¾" steel tube is permitted. Any fabricated shaft must have a least 1 (one) U-joint approximately midway between the steering wheel and the steering box as an impact break point. U-joint must be properly supported with a heim or bracket.

  2. A master electrical switch disconnect must be clearly marked with "on" and "off" with a maximum 1 (one) inch light. It must be clearly visible to safety personnel. All electrical wiring must be in full view and not shielded from visual inspection.

  3. A window net is required.¾" webbing with a quick release latch on the top.

  4. All oil pressure gauges must have copper tube or braided lines. Plastic capillary tubing is NOT allowed.

  5. A fully charged fire extinguisher with an indicator gauge is required. It is recommended that it be securely mounted with a metal quick release bracket and easily accessible.

  6. Only 1 (one) battery permitted. It must be securely mounted with metal straps over battery and bolted down. If mounted behind the driver compartment, it must be enclosed in an, appropriate box with a metal_strap over the top and bolted down. ,

  7. Original braking system is required. NO adjustable proportioning valves. NO rear disc brakes allowed. Front drums may be converted to OEM disc brakes for vehicle type. Power brake booster may be removed for manual (OEM) bra e master cylinder. ALL 4 brakes MUST be operational.



4. The minimum requirement for NO front windshield is 4 (four) evenly spaced bars of 3/8" or larger placed in front of driver, welded to the roll cage. NO glass or acrylic windshields are allowed. A Lexan windshield is highly recommended with a minimum of 3 (three) evenly spaced I" flat metal braces mounted in the center of the windshield.

  1. Body must remain as manufactured however, body parts can be swapped. (Fenders, quarter panels, and doors are OEM ONLY). The body must be stripped of all glass, trim, lights and upholstery. Lightening of the body is restricted to the removal of bolt on pieces only. Any holes in firewall, rear bulkhead and floor must be sealed.

  2. Roof, hood and trunk MUST remain OEM. Fenders and rear quarter panels can be aftermarket but MUST be 227gauge steel ONLY. NO ALUMINUM. Doors may be constructed of no thinner than 22-gauge steel. Webbing may be removed from hood and trunk. Original functional hinges and springs are optional, must be pinned shut. Doors, fenders and Quarter panels may be REPAIRED with 22-gauge steel. Patch panels can only be 12" x 12" patches (144 square inches). Doors must be welded or riveted shut. NO sheet metal screws allowed anywhere on the car. NO homemade 22-gauge steel bodies allowed.

  3. Trimming of the wheel well to allow for tire clearance is permissible. No other cutting on body allowed

  4. Side skirts are allowed but must not be lower than stock rocker panel.

  5. OEM interior floor, rocker panel and firewall required. Rear trunk floor may be replaced with minimum 22-gauge steel metal.

  6. Front and rear bumpers must remain in stock location. OEM bumpers must be retained to the car with chains or cables to prevent loss from impact. Original front bumper brackets may be welded to the frame for safety. Front and rear bumpers must be OEM type steel bumpers; front and rear bumper covers allowed as long as the stock bumper is mounted in stock location inside.

  7. No side nerf bars or bumper loops. Original front bumper brackets may be welded to the frame for safety.

  8. Non-operational hood scoops are allowed with a maximum 3" height and maximum 18" width.

  9. Rear spoilers are allowed. Maximum 4" tall with maximum 70-degree angle and maximum 60" wide. Must be¼" clear Lexan. NO side traps.



5. A positive acting throttle linkage with a minimum of 2 (two) return springs mounted on two separate brackets is required. A toe kick is required on the gas pedal.

  1. A drive shaft loop of¼" x 2" steel strap or I" round steel tube is required. It must be located no further back than 6" behind the FRONT U-joint. Drive shaft must be steel and painted white.

  2. Frame must be stock; NO modifications. (EXCEPT for spring slot adjusters.)

  3. Any rear wheel drive intermediate passenger car with a minimum factory produced wheelbase of 107'' is eligible for competition. Wheelbase must be stock for that year. Make and model claimed must be within ½" tolerance from left to right.

  4. No pony cars (i.e., GM F bodies, Mustangs, Camaros, etc.), trucks or SUV's permitted. Please check with the Tech official if you have any questions about eligibility of model before you begin building.

  5. All chassis components must be unmodified, original OEM type or direct service replacements for the vehicle year, make, and model claimed. This applies to all front and rear suspension components and the steering assembly. Aftermarket power steering pump, brackets and hoses are optional. Steering Quickener optional.

  6. Sway bars must be OEM, not modified and must be mounted in stock location. Sway bars may be adjustable at outer ends to lower control arm only.

  7. Shocks must be steel, stock appearing and mounted to the chassis with OEM stock mounting hardware. All suspension components must be mounted using OEM stock points and as originally produced. ABSOLUTELY NO modifying or relocating of any mounting brackets. NO disassembly type shocks allowed.

  8. Springs shims or the 5-inch adjustable spring spacers will be considered acceptable weight jacking devices. Coil spring cars must have 5 or 5 ½" springs permitted. Front frame may be slotted for springs adjuster. No other modifications to frame.

  9. Steel control arm bushing permitted. No offset bushing allowed of any type.

  10. Ballast permitted. Must be securely mounted, painted white and have class and number clearly marked on it. No weight boxes are permitted. Any ballast must be mounted to the stock floor pan, roll cage, or frame with ½" nuts and bolts with large diameter washers .

  11. Minimum weight requirements vary depending on your transmission. 4-speed manual transmission weight allowed 3350 lbs. with 54% left side weight, with driver. Automatic weight allowed is 3500 lbs. with 54% left side weight, with driver.

  12. Minimum ride height is 6" to bottom of the lowest frame rail with the driver.



6. All cars must use OEM differential and rear axle s, family to family interchange permitted.

  1. No spools. Limited slips, welded spider gears, etc. are permitted .



7. Engine must be mounted in stock location with stock style mount. Steel allowed . NO SET BACK OF ENGINE. Engine must be centered with in ½" left or right of chassis centerline .

  1. Engine must be stock type for the make and model. GM for GM, Ford for Ford, etc.

  2. ARP type fasteners allowed.

  3. Engine compression, periodically checked, may not at any time exceed 10: I.


  • 350 Chevy block or smaller. 351 Ford block or smaller. 360 Chrysler block or smaller.

  • Overbore of 0.0650 maximum .

  • No other modifications to engine block. Block must remain exactly as produced by manufacturer. De-burring is permissible.

  • Pistons must be OEM or Hypereutectic replacement. Flattop or dish only. Pistons must use stock ring dimensions.

  • E Crank weight 51 lbs. NO knife edging

  • Rods must be stock or stock replacement. Aftermarket rods allowed as long as they are steel I-beam design stock stroke. NO lightweight or Aluminum rods.


F. Oil pan must be steel and stock appearing.

G. A I (one) inch plug must be installed in the oil pan for inspection. The access hole must be in line with a connecting rod journal. If hole does not exist, and inspection is required, oil pan must be removed or disqualification will result. DRIVER JS RESPONSIBLE FOR PULLING



H. Crankshaft must be stock OEM or stock replacement only with stock stroke. No strokers.

I. Damper must be stock elastomer type (stock OEM type).

J. Any type V belt pulley allowed.


K. Any OEM steel, straight plug, stock production cylinder head may be used. NO VORTEC HEADS.

L. Pinning of stock type press-in rocker studs will be allowed. Screw-in rocker studs and guide plates will be allowed. OEM stud size only. No stud girdles allowed.

M. No aftermarket, "bowtie", aluminum, high performance, or altered performance heads allowed.

N. No grinding, match porting or polishing of cylinder heads allowed.

O. Only stock diameter single valve springs with or without damper may be used. Steel retainers only. Max valve springs pressure must not exceed 120 psi (pounds per square inch) on the seat. BEE HIVE SPRINGS OPTIONAL.

P. No titanium, hollow, or undercut valve stems. Stock valve stem size only.


Q. Any stock OEM unaltered cast iron intake manifolds allowed. NO VORTEC OR MARINE INTAKE MANIFOLDS.

R. Optional aluminum intake manifolds will be as follows:

  • Chevrolet - Edelbrock part #2 IO1. Older versions carrying the same part number will not be allowed.

  • Ford- Edelbrock part #2181. Windsor motors only. Chrysler - Edelbrock part #2176

Manifolds must remain unaltered, box stock only. No grinding, match porting or polishing of intake manifolds allowed.

S. No vacuum leaks.


T. Hydraulic flat tappet cams only. (NO 4/7 swap cams allowed.)

U. Lift may not exceed 500 lift. Camshaft lift will be measured at push rod 0.333 maximum lobe lift.

V. No solid lifter, roller lifters, or stud girdles allowed.

W. Only OEM type lifters, push rods, and rocker arms.

X. Only stock rocker ratios allowed. Chevy 1.5, Ford 1.6, Chrysler 1.5. NO roller rockers.

Y. Aftermarket valve covers allowed . (revised l.29.17)

7.4 All makes must display CID and minimum weight on right and left side of hood, 2" tall.

7.5 Stock engine rebuilds allowed.


7.6 OEM type mechanical fuel pump is required. NO electric fuel pumps permitted.

7.7 Box Stock Holley #R4412 2 barrel 500 CFM must meet Holley specifications and must pass track gauges (allowed on both aluminum intake and cast). OEM carb allowed with NO modifications and may only be allowed to run on stock OEM cast iron manifold. (Quadra Jet)


7.8 No polishing, grinding, or drilling (i.e ., Metering blocks) of holes allowed.

7.9 Choke horn must remain. (Do not mill or remove). Choke, blade, and rod may be removed.

7.10 Size and shape of boosters must not be altered.

7.11 Booster height must remain stock.

7.12 Jets of any size may be used.

7.13 Venturi area must not be altered in any way.

7.14 Casting ring must remain completely visible and may not be removed .

7.15 Base plate must not be altered in size or shape.

7/16 No holes may be drilled in the base plate.

7.17 Stock butterflies must not be thinned or tapered.

7.18Screw ends may be cut even with the shaft, but screw heads must remain stock.


7.19 Throttle shaft must remain standard and must not be thinned, cut or nicked in any manner.

7.20 A carburetor adapter/spacer is permitted with a maximum of l" thickness for Holley and Quadrajet.

7.21 Choke plate and linkage may be removed.

7.22 All cars must use track fuel. NO E85 ALLOWED. Cool cans are not allowed. Track fuel will be dyed for tech purposes.


7.23 Aluminum or stock radiators in stock location permitted.

7.24 Radiator may be mounted with a I" steel tube frame and may not extend past the front bumper.

7.25 Catch cans are required. Must be metal or a racing designed until with a minimum capacity of I quart. Stock plastic over flow tanks are not permitted.

7.26 Must be vented to the passenger side base of windshield.

7.27 Engine driven cooling fans and OEM type water pumps required. Electric accessory fans permitted.


7.28 Ignition system must be OEM type with OEM or direct service replacement parts.

7.29 No aftermarket performance distributors, coils, or control boxes allowed.

7.30 May use any type of spark plug.

7.31 Firing order must remain as manufactured.


8. All cars must use production line installed automatic or manual transmission. OEM 3 or 4 speed manual transmission allowed. All working gears; forward and reverse must work. Stock weight 11" clutch and flywheel. Weight allowed is 3350 lbs. with 54% left side weight. Automatic transmission car must have minimum 11" fully functional torque converter; minimum 3 (three) forward gears. NO POWER GLIDES. Automatic transmission car must weight 3500 lbs. with 54% left side weight.

  1. All shifter positions must be operational. Any aftermarket shifter with a positive revers lock out is highly recommended.

  2. Auxiliary transmission coolers are permitted; must be securely mounted outside of the vehicle interior. All cooler lines must be metallic. Rubber tubing may be used to connect line to transmission or coolers. Each rubber connection may be no longer than 1O" and must be properly clamped.

  3. Transmission must be mounted in the original stock rubber mounts to the original cross member.


EXHAUST: ( re, is ed 3.24.17)

9. Stock exhaust manifolds permitted. 2-1/4" max. diameter NO race headers ste headers or center dumps etc. allowe

  1. Vehicle must have an exhaust system that exits behind the driver.

  2. One pipe per header. Vehicle must be less than 103 dB (decibel) as measured from the grandstands.

  3. Floor pan may not be cut or modified for exhaust clearance.



10. ONLY steel wheels are permitted. Maximum width is 8". All 4 wheels must have the same back spacing.

  1. NO balancing weights.

  2. All cars must use track tires. NO alterations to tire tread or compound allowed.

Wheel studs must have sufficient thread engagement to protrude through lug nut; Competition I" hex lugs are required. Competition 5/8" wheel studs are highly recommended.