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2018 Street Stock Rules

2018 Montgomery Motor Speedway Street Stock (REVISED)

The rules and/or regulations set forth herein provide for the orderly conduct of racing events and to establish minimum acceptable requirements of such events. These rules shall govern the condition of all such events. All participants are deemed to have complied with these rules. No expressed or implied warranty of safety shall result from publications of or compliance with these rules and/or regulations. Rules are intended as a guide for the conduct of the sport and are in no way a guarantee against injury or death to a participant.

* Speedway Officials shall be empowered to permit minor deviations from any of the specifications herein or impose any further restrictions that in his/her opinion does not alter the minimum acceptable requirements. No expressed or implied warranty of safety shall result from such alteration of specifications.

*Speedway reserves the right to update, modify, and/or delete rules at any time deemed necessary to insure safety, fair competition or any other reason that may be appropriate.

*Cars, parts and or equipment will not be considered as having been approved by having passed through inspection at any time or number of times unobserved or undetected.

*Any interpretation or deviation of these rules is left to the officials. Any decision of and by Speedway Officials is final.

*Unsportsmanlike-like conduct may carry a minimum $100.00 fine and/or suspension.

Drivers are responsible for their crews and family

*Please refer to General Rules section for Conduct, Race Procedures, Inspections, Mechanical Protest, Common Technical Rules and other information.

*Illegal parts can and may be confiscated by tech officials (If you don’t want to lose it don’t bring it)


    1. These rules are intended to produce a fair and competitive field of cars and are subject to change as needed, without notification or justification. MMS Management reserves the right to refuse any competitor without reason or justification. The intent and interpretation of the rules will be the decision of the Race Officials and MMS. If there are any questions regarding the legality of any part(s), the burden of proof lies with the competitor.
  • All suspension components except springs and shocks must remain OEM stock for make and model of chassis used and may not be altered in any way. Unless specified in these rules.


  1. Top 5 inches of windshield is reserved for division sponsor. Sponsor decal provided by MMS. Failure to display division sponsor may be grounds for forfeiture of purse and points for event
  2. Contingency sponsors decals must be displayed in designated areas on race car in original form to receive Gift certificates, Prize Monies etc. From Contingency Sponsors.
  3. All cars must meet track noise level specification of 100 db at 100 ft.


  1. Minimum weight 3200 lbs. with 53.0% maximum left side weight. One pound per lap “Burn off” allowance after the race. Must maintain 53% maximum left side weight


  1. Complete body (bumper-to-bumper) must remain stock. Stock Appearing / Aftermarket Body Permitted (example: Five Star/Performance Bodies Street Stock Body) (Steel or Aluminum). Fiberglass or Composite hood and roof permitted.
  2. No sectioning, chopping, channeling, hulling or cutting of any kind, except for tire clearance and roll bars only.
  3. Hood, roof, trunk lid and trunk may be gutted.
  4. All holes in front and rear firewall and floorboard must be covered with 16-ga. steel.
  5. Front firewall must remain in car in the stock OEM location. Any deviation from this must be approved by Tech Officials.
  6. Body must mount in the stock location or subject to weight penalty.
  7. All body parts must maintain a minimum of 6″ ground clearance. No tolerance.
  8. Aftermarket nose and tail pieces may be used, but must match car.
  9. Stock Type steel or aluminum doors or approved replacements.
  10. Rear Spoilers may be used. Maximum 6″ high by 60″ wide centered. Clear Polycarbonate recommended (Lexan) All Bodies Subject to approval by MMS Tech.


  1. 108″ minimum wheelbase.
  2. Full-frame models and Unibody GT type cars (i.e. Camaros, Firebirds, Mustangs or Novas etc.). No front wheel drives or strut suspension vehicles. MMS X-Y-G aftermarket frame allowed. MMS X-Y-G front and rear clip allowed. Frame and clips must be purchased through Montgomery Motor Speedway. All MMS X-Y-G frames and clips must have MMS ID Plates.
  3. Frame must be fully stock, with stock location pick up points
  4. Bracing, boxing and X bracing permitted. Left front Caster/Camber perch adjustment OK.
  5. Fuel Cell Protector Bar required mounted between fuel cell and bumper bar
  6. Minimum four-point roll cage with four driver side and three passenger side door bars (1/8 inch minimum plate covering driver’s side door bars.) gussets recommended on all 90* angles on driver side of cage.


  1. 6″ minimum frame height. No tolerance.
  2. Stock springs 5″ inside diameter minimum.
  3. May use adjuster cups (screw-type) inside spring buckets.
  4. Screw or Weight jacking bolts allowed in the front and rear.
  5. Front Upper Control Arms OEM or Spec Other approved cars (GM/Ford/Dodge cars will be allowed approved tubular upper control arm/ MMS must approve)
  6. Lower Control arm must be OEM or Tubular Lower A-Arms from Johnson Chassis Part # JCI-09-02-01


  1. Steel body, Nonadjustable shocks, must cost $150.00 each or less. Track reserves the right to buy shocks. No bump stops or suspension limiters allowed. Out Board Shock Location Allowed


  1. Front sway bar (hollow) 1 1/4 “Maximum diameter, can be floating style and fully adjustable.
  2. Must mount in stock location on frame rails and may adjust on ends.


  1. Positrac, limited slip, mini spool or unlocked optional.
  2. No Gold Trac or ratchet type units.
  3. 10 Bolt, 12 Bolt or 9 inch Ford Floater permitted. All points must be in “stock” location from manufacturer.
  4. Required right rear racing axle. (“MOSER” type.)
  5. Pinion angle can be adjusted. Only by drilling upper control arms at rear end.



  1. Stock Type Brakes/calipers only (front and rear). All 4 must be in working condition
  2. Duel Master Cylinder allowed. Only one brake bias adjuster allowed in driver compartment.   
  3. 8″ Steel wheels – type optional.     
  4. Large lug nuts (1″) required with 5/8″ studs minimum.
  5. NO pop-off or bleeder valves.
  6. Tracking width same front to rear must be within 1 inch. No wheel spacers allowed.
  7. Maximum 3” camber. Measured at the wheel.
  8. Aftermarket Steel Rotor required for right front wheel only
  9. MMS Track Tire Hoosier 890. No soaking or altering of tire in any manor allowed. Drivers soaking or altering tires will forfeit all purse and points for the event. Driver must also pay a $1,000 fine prior to being allowed to compete at Speedway. Any illegal tire, in the judgment of Speedway Officials, will be confiscated.


  1. 360 CID limit.
  2. .060 maximum over-bore.
  3. Stock block, bore and stroke for engine.
  4. Engine must maintain minimum of 12″ ground clearance. Cross member must remain unmodified.
  5. Engine must mount in stock position.
  6. Unaltered General Motors Crate Engine #88958602 may be substituted. The Engine must remain sealed at all times. Certified Sealed Engine Alliance leaders S.E.A.L. Rebuilding Seals permitted (May also be required to have speedway stamping/seal)


  1. Stock cast iron heads with casting numbers only. Maximum Compression Ratio 10.5 to 1.
  2. No Aluminum heads allowed (except for crate engines).
  3. No angle plug heads (Ford and Chrysler excluded).
  4. Angle milling permitted.
  5. Screw in studs, guide plates and poly locks optional.
  6. Any questionable heads must be approved by Chief Tech Inspector.

 Maximum Valve Size

  1. Chevrolet: 1.94 intake/1.50 exhaust
  2. Ford: 1.94 intake/1.60 exhaust
  3. Chrysler: 2.02 intake/1.60 exhaust
  4. Only magnetic steel valves, springs, retainers and locks.
  5. No Titanium valve train parts.
  6. Stud girdles permitted.
  7. Bowl work permitted from valve seat to valve guide boss. No work permitted in runners or the short turn radius.
  8. Stainless valves okay.
  9. Stock diameter valve springs only.
  10. No acid etching or gasket matching.


  1. Stock OEM production or stock replacement crankshafts only. Minimum weight on crankshaft 50 lbs. No tolerance. May not be lightened or otherwise altered except for balancing



  1. Stock steel replacement rods only.

Maximum Rod Length

  1. Chevrolet: 5.7 or 6.0
  2. Chrysler: 6.123
  3. Ford: 6.0
  4. Floating pins OK.
  5. Two or Four valve relief, three-ring pistons with magnetic steel pins.
  6. Valve reliefs may not be polished or de-burred.
  7. Pistons may not extend out of block.


  1. Maximum lift .450 at the valve
  2. Hydraulic camshafts only (Must be magnetic steel) NO tolerance!!!!
  3. Cam lift determined by measuring lift at the lifter, then multiplying by rocker arm ratio.
  4. No solid, roller, ceramic or mushroom valve lifters permitted.
  5. No modifying of lifters (must be magnetic steel).
  6. Lifters must be of stock size for make (0.842 Chevy; 0.875 Ford; 0.900 Chrysler.)
  7. Only stock length magnetic steel push rods.
  8. Stamped steel/Roller tip 1.6 ratio rocker arms only for Ford.
  9. Stamped steel/Roller tip 1.65 ratio rocker arms only for Chrysler.
  10. Roller tip cast steel rockers permitted. NO Aluminum, Roller Bearing or individual Shaft Mount rocker arms.


  1. Stock cast iron intake manifolds or aluminum permitted. (Chevy #2101; Chrysler #2176; Ford with 4 barrel heads #2665, Ford with 2 barrel heads #2750, Ford Windsor #2 181.) Intakes allowed for Vortec heads Edlebrock #7116 or GM part # 12366573 (Revised 1/13/16)
  2. No high-rise or marine intakes. NO porting, acid etching, polishing or gasket matching.
  3. Must retain stock casting numbers and firing order.
  4. 1” tall max Aluminum or Phenolic carburetor spacer must be centered on intake. Holes must be cut perpendicular with the base of the carburetor. NO tapers or bevels!


  1. Stock cast iron exhaust manifolds or Headers.
  2. No porting, polishing, acid etching or gasket matching.
  3. Cross-member cannot be modified to fit manifolds or headers.
  4. Exhaust must exit behind driver and terminate under car. 3″ maximum pipe diameter.
  5. Header 1 5/8″ maximum, Collector type, No merge collectors.


  1. High volume/pressure oil pumps okay.
  2. Must mount in stock location.
  3. Oil pan allowed must have 1″ inspection plug in line with crankshaft casting number Or 100 lb. weight penalty.



  1. Stock type HEI ignitions only.
  2. MSD soft touch rev limiter part # MSD-8728 required with a 6400 chip or Part # MSD 8727 set at 6400 RPM. Must be mounted out of drivers reach with zip tie wrapped and taped in place.


  1. Holley 2300 model #7448 (350 CFM) carburetor only. Must fit all gauges/tools.
  2. For General Motors Crate Engine #88958602 only: Holley # 0-80507-1 (390 CFM) carburetor must be used, which must fit all gauges/tools and remain unaltered from factory new condition, except for jets
  3. No cold air boxes. May remove choke assembly. Choke horn must remain stock. NO carburetor air direction/flow devices, Paper type or K&N style air filter permitted.


  1. Automatic or Standard transmissions allowed.

Standard Transmissions

  1. OEM production transmissions only. No lightened or polished parts.
  2. Stock clutch assembly 10 1/2″ minimum. Minimum weight of 32 pounds.

Automatic Transmissions

  1. Must run full functioning torque converter 11 inch minimum.
  2. Stock production transmission can be a performance built stock unit.
  3. No direct pump drive converters.
  4. Steel braided hoses are required for cooler lines.


  1. Steel drive shafts only and must be painted white with the car number clearly displayed.
  2. Must run a minimum of two drive shaft safety loops.


  1. Fuel cells are mandatory. The maximum capacity allowed is 22 gallons. Fuel cells must have a working check valve and foam. OBERG Fuel Line Safety Valve #SV-0828 required or SRI Part # FFF-FSV
  2. Fuel cells must be mounted equal distance between rear frame rails and at least 8 inches above the ground.
  3. Fuel cell must be mounted inside a steel box.
  4. Fuel cell vent and overflow may not exceed 1 inch in diameter. Overflow must exit to the rear.
  5. Fuel cell must have four 1/8 inch x 1 inch straps under cell can and at least two straps on top of cell bolted to fuel cell frame.
  6. Fuel cell must be protected at rear by one protector bar extending below rear of frame beyond bottom of cell and the width of the cell, with one center brace.
  7. Fuel lines must be run in metal tubing or metal conduit if routed through the driver’s compartment.
  8. No electric fuel pumps or pressurized fuel systems.
  9. Track approved fuel only Sunoco 110 or 102 crate fuel, No exotic blends or methanol, No nitrous oxide, nitro or any other oxygenating agents permitted.


  1. No antifreeze ($100.00 fine) Water Wetter allowed.
  2. Added weight must be securely bolted in place. Dislodged weight cannot be returned to car for weighing after race. All added weight must be painted white with car number in red or black. Any lost weight will result in a $10 per pound fine to the Driver.
  3. All cars will be subject to tech approval and must display a MMS Technical Department sticker issued by tech officials before being allowed to race.


  1. Battery master disconnect switch installed on driver’s side of dash or within easy access from driver and either window.
  2. Seat belts, window net, driving gloves, shoes and racing suit must have non expired SFI dates.
  3. Fire extinguisher required within reach of the driver.
  4. Minimum single layer racing suit (SFI-3.2A/1 rating).
  5. Driving Gloves (SFI-3.3A/1 rating).
  6. Helmet with Snell M2005 minimum rating. No older than 5 years from manufactures date.
  7. Mandatory 360 degree Neck Brace. Head and Neck Restraint system highly suggested and recommended (i.e. Hans head and neck restraint system / Impact racing Rev. / Simpson Racing Head and Neck restraint system)
  8. Safety Belts (SFI-16.1 rating). No older than 5 years of the manufacturers date.
  9. Window Net (SFI-27.1/1 rating). Racing Shoes (SFI-3.3A/5 rating).



    1. The definition of stock is as produced from the OEM factory. Weight / RPM penalty may be added to cars not conforming to rules. Drivers or cars found illegal may forfeit all points and money earned for the entire event and possible suspension and/or fine.
  • All cars must meet track noise level specification of 100 db at 100 ft.




© 2018 Montgomery Motor Speedway

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