2021 Rules the Charger Division will be Following that are used at Dillon Motor Speedway

Challenger Rules 2024

For Reference of Past Charger Rules at SNMP

2021 Charger Rules


1970-2019 rear wheel drive cars with a minimum wheelbase of 104” Wheelbase.



  1. All cars must have a minimum of (2) doors, (2) fenders, (2) rear quarter panels, deck lid, back bumper Cover, roof and hood. Open wheel type bodies allowed with track tech approval.
  2. All bodies must meet roof and spoiler height template specifications.
  3. All bodies must be speedway approved. Roof height is 48” from 10 inchs back from center of windshield.
  4. Rocker panels may be fabricated; rocker panels, body height and nose must maintain 4” ground clearance.
  5. Front and rear windshields must be full Lexan. Clear Lexan or plexiglass may be installed in the rear quarter windows. No side windows.
  6. Speedway approved window net must be installed in the driver’s side window opening.
  7. Max overall spoiler height is 40”.
  8. Rear spoiler 5” high with maximum 60” width (max 300 square inches).
  9. Wrecker hookup required front and rear of car.


  1. Stock OEM front sub frame with tubing frame connector allowed with complete stock floor pan 3050 lbs. 55% Max Left side weight
  2. OEM stock clip must have factory OEM mounting points for weight break. Rear trailing arm mounts may be fabricated. Can be tubed from firewall back 3100 lbs. 55% Max Left side weight
  3. Full tube chassis allowed, total weight 3150 lbs. 55% Max Left side weight.
  4. Straight Rail Chassis allowed total weight 3200lbs. 53% Max Left side weight.
  5. Frame rails minimum 2”x 3”. Weight boxes are legal.
  6. Chassis rails must maintain 4” min – 5.5” max ground clearance with driver.
  7. A Steel firewall must separate the driver from the engine compartment and fuel tank.


  1. A complete SNMP approved roll cage.
  2. Roll cage must be constructed of roll bar tubing with a minimum outside diameter of one and half 1 ½” inches x .083 wall thickness.
  3. Roll cage must be centered on the frame. Perimeter style. (No off set chassis)
  4. Main roll cage uprights must be on top of outside frame rails.
  5. Full cage is required with four uprights and four top bars.
  6. Roll bars may go through front and rear firewalls.
  7. Minimum of four bars in driver’s and passenger’s door required.
  8. All bars within driver’s reach must be padded.


  1. Adjustable cups allowed on front and rear.
  2. Spring spacers or screw jacks may be used on front and rear.
  3. OEM type steering box. Aftermarket tie rods, centerlink, idler, pitman arm, allowed.
  4. OEM stock spindles required. Cutting or aftermarket allowed. Ball tapers may be drilled.
  5. Lower A-frames must be OEM Design. Lower A-Frames must be same length. Aftermarket lowers can be used but must conform to OEM Design if the car is adding the weight for the fab clip.
  6. Upper A-frames may be fabricated.
  7. Front sway bar may be OEM or aftermarket. Mounting points may be aftermarket. Sway bar size can be no bigger than 1 1/2″ with 1 1/4″ ends.
  8. Leaf spring and/or coil spring suspension allowed. Slider allowed.
  9. Steel rear lower trailing arms required.
  10. A fabricated metal top link and track bar allowed.
  11. Damper shocks may be used.
  12. Rubber bushing, metal bushing, Teflon bushings or heim joints allowed.
  13. Lowering blocks and trailing arms may be adjustable.
  14. Aftermarket or OEM 5×5 design hubs allowed (All wide five wheels must be approved by Track Official)
  15. No bump stops or travel limits on suspension. No coil binding allowed.


  1. Rear end may be car, truck, or floater. Quick change allowed (older style no light weight, winters sprinter or tigers). Tubes and axels must be steel. Any ratio. No low drag or polished parts allowed. Newer style quick change permitted with 25 lb weight penalty added.
  2. Detroit Locker, or locked rear end only. No Gleason or Quicktrack.
  3. No Cambered Rear End Housings. +/- .4 Grace.
  4. No light weight 10″ or smaller center sections.


  1. Tie rod or spherical end shocks allowed. OEM aftermarket Struts allowed. Coilovers are allowed.
  2. Aftermarket metal body shocks allowed. Can be adjustable one way. No canister shocks allowed. Coil springs minimum diameter 5”.  Schrader valves allowed.
  3. NO Travel Limiters, Chains, Cables etc. Allowed.
  4. No composite leaf springs. All cars must compete with type of springs from OEM. If coil, it must be coil. If leaf, it must be leaf. Coil over eliminator allowed only on rear.


Any Competitors shocks may be claimed by another competitor in the same class.  Competitor claiming shocks must finish in a position behind the competitor whose shocks they are claiming.

The Competitor claiming the shocks must do the following for the claim to be correctly done:

  • $500 (cash)
  • Written statement must be given to the Head Tech within 10 minutes of completion of the last lap of the competitors event
  • Written statement must have the following information on it
    • Name of Competitor making claim
    • Finish Position of Competitor making claim
    • Name of Competitor whose shocks are being claimed
    • Finish position of Competitor that shocks are being claimed from (Driver making claim must finish in a position behind the Competitor of the shocks being claimed)

Failure to comply with this claim rule will result in a $500 fine, loss of points for that event, loss of finishing position for that event and suspension.

Hardware for shocks is not included in the claim. 



  1. Single piston steel OEM stock brake calipers required. All 4 wheels must work.
  2. Steel disc brakes may be used on front and rear.
  3. Aftermarket brake and clutch pedal allowed.
  4. Dual master cylinder allowed. Any type Brake bias adjusters allowed.


  1. 104” minimum wheelbase.
  2. Cars must not exceed the maximum allowable tread width of 65 inches plus or minus 1/2.
  3. Treadwidth must be obtained through wheel spacers and rim offsets only. Not suspension modifications.

ENGINE A CRATE ENGINE chev#88958602, chev#88958603

  1. This Crate engine must remain within factory spec and as supplied from factory manufacture. These engines are subject to teardown procedures and legalities determined by tech.
  2. Crate engines are designed to cut the cost of racing. Anyone found tampering with these engines will be fined for each offense and loss of points.
  3. GM 603 and 602 Crate engines may run a 390 CFM Carb 4bbl per NWAAS Late Model Stock Car guidelines with 1” spacer (Single Open Hole or Four Holes)
  4. Ford 347JR Crate engine may run a 390 CFM Carburetor 4bbl per NWAAS Late Model Stock Car guidelines with no spacer. 


  1. Only stock production engines allowed. Chevrolet 362 cubic inch maximum, Ford 358 cubic inch, Chrysler 365 cubic inch.
  2. No polishing or coating inside of block.
  3. Aftermarket stock length replacement rods allowed.
  4. Only solid steel connecting rods permitted. No polishing or machine work will be permitted.
  5. Replacement rods may not be lighter than OEM stock rods.
  6. Connecting rods must be stock length for make and model of engine used. For Example, Chevrolet 350 – 5.7 Rods
  7. Flat top or dish 3 ring pistons permitted. Piston must not extend above top of block.
  8. Crankshaft with stock stroke must be retained. Minimum weight 50 lbs.
  9. Crankshaft must not be Knife-edged. No excessive machining or grinding other than balancing. No drilled rod or main journals. Subject to template inspection by Tech Official.
  10. Wet sump oil system only.
  11. Enlarged oil pan allowed. Kick outs will not be permitted between the bolt holes’ flange and the top of the added sump. Oil pan 4” minimum ground clearance.
  12. No electric fuel pumps allowed.
  13. Aftermarket valve covers allowed.
  14. Aftermarket pulleys allowed.


  1. Stock OEM production steel heads only. No Vortec heads on built engine. No Bowtie Heads. RHS heads not allowed.
  2. World Products Stock Replacement SR #043600 allowed (EQ Stock replacement is allowed) with a 50 lb. Weight penalty (350 Carb).
  3. NO modifications, no porting, polishing. No grinding of any kind. 3 angle valve job ok as per Speedway rule. One cut below valve seat, to bottom of valve guide. Do not radius or blend bottom of cut below valve seat.
  4. Chevrolet 58cc minimum; Ford (Clev) 52cc; Ford (Win) 56cc; Chrysler 62cc minimum.
  5. Steel valves required. Valve size maximum:
  6. Chevrolet 2.02 intake 1.65 exhaust
  7. Ford Cleveland 2.05 intake 1.65 exhaust
  8. Ford Windsor 1.89 intake 1.60 exhaust
  9. Chrysler 1.90 intake 1.60 exhaust


  1. Hydraulic or flat tappet cam and OEM diameter lifters with no maximum lift
  2. Any steel type timing chain allowed.
  3. Steel retainers required on valve springs.
  4. Screw in studs and guide plates permitted with any ratio roller rocker arms allowed.
  5. Stud girdles are permitted. Poly lock allowed.
  6. 4-7 Swap cam shafts will not be allowed


  1. Cast Iron two-barrel intake or Edelbrock performer aluminum intakes. Chevrolet #2101/ 2116 Ford

Windsor #2181, Cleveland #2665, #2750 and Chrysler #2176 or P#4532852. No RPM versions.

  1. No porting, polishing, or grinding will be permitted. Do not touch it.
  2. Holley #7448 spacer a maximum ¾” metal spacer with 2 holes (max 1 ½ 1.502) centered in spacer with a straight cut. No Bevels. Spacer Gaskets .065 max thickness.
  3. Holley #4412 spacer a maximum ¾” metal spacer with 2 holes (max 1.690) centered in spacer with a straight cut. No bevels. Spacer gasket .065 max thickness.
  4. All carburetors and spacer plates must meet speedway specifications. 


  1. Holley #4412 2bbl carburetor “500” allowed on all engines with stock OEM straight plugged heads and built by NWAAS built engine guidelines for bottom ends.

All other built engines must run a Holley 2300 2bbl carburetor model #7448 “350” per LLM guidelines


  1. Engines may be interchanged from one body manufacturer to another.
  2. Engine must be centered in chassis. #1 spark plug in line with upper ball joint.
  3. Minimum crankshaft height is 12”, from the center of crank pulley to the ground.


  1. Round air cleaner element minimum of 12 inches; maximum of 17 inches.
  2. Element must be minimum of 1 ½ “and a maximum of 4 inches in height.
  3. Dry type paper element only. No cold air boxes or cowl induction allowed.
  4. No tubes, funnels or anything which may control the flow of air are permitted.
  5. Air cleaner base must not be above choke horn. 


  1. OEM standard production Automatic, or Manual transmissions only.
  2. Heavy duty OEM steel clutch permitted.
  3. A 7 ¼” and 5 ½” clutch will be allowed with a 25lb weight penalty.
  4. Hydraulic clutch control permitted.
  5. Must have steel bell housing that is speedway approved.
  6. Drive shaft must be of magnetic steel only (2 ¾ min dia). Drive shaft must be painted white with two safety loops attached to the bottom of car.


  1. Headers (4 into 1) will be permitted. No stepped headers. No 180, or crossover allowed.
  2. Cast iron manifolds permitted.
  3. All LH exhaust must exit behind the driver.


  1. Aluminum radiators permitted. Any radiator allowed.
  2. Overflow hose recommended.
  3. Antifreeze is not permitted.


  1. Electronic or point type OEM ignition allowed.
  2. Aftermarket distributors permitted.
  3. Only 1 racing coil permitted.
  4. Only one 12-volt battery permitted.
  5. MSD ignition box allowed. No adjustable timing controls.
  6. No open ended wiring in driver’s compartment.
  7. Any type traction devices are not allowed. No computerized systems are allowed.
  8. All ignition systems must be acceptable to speedway officials.


  1. Track fuel required. Must purchase fuel from track. No other mixtures of any kind.
  2. All Fuel must pass SNMP Fuel specifications. Fuel must be same color and pass a specific gravity test
  3. Fuel cells are recommended. Must be securely strapped down with no less than 1/8” steel
  4. straps. Fuel cell must be vented high and to the left side.
  5. The maximum capacity allowed is 22 gallons.
  6. Fuel cells must have 10” minimum ground clearance.


  1. Maximum width 10” on all 4 wheels. 15” Steel wheels only. No 2 in back space allowed.  ALL $ WHEELS MUST BE THE SAME.
  2. Air bleeders will not be permitted. No chemical tire treatment allowed.
  3. Hoosier F-50 for all events. All SNMP events, tires will be purchased from the tire building on race day. Drivers/Tire Specialist will purchase tires and will draw a pill to receive their stack for the event. All tires are graded and stacked by a Southern National Motorsports Park Official.
  4. Any car tires from any source other than speedway tire building will be disqualified.


  1. Weight of car must be on back of hood on drivers side.
  2. All cars will be weighed with driver in a driving position.
  3. All lead weight must be added to chassis securely.
  4. Cars may gas up after race.
  5. No tungsten allowed.
  6. Light weight quick change 25 lbs added. Older design no weight penalty 


  1. These rules are subject to amendments for competition when ample notice has been given by the speedway.
  2. Any car that does not conform to the above rules may be allowed to compete with a weight and/or restrictor plate at the tech committee’s discretion.
  3. Speedway officials may use professional judgment for any infractions for a competitive race program.
  4. Coil over chassis permitted as long as it fits shock and sway bar rule for this division. Any chassis or suspension to have a clear advantage are subject to weight additions per competition director’s discretion.