Street Stock/MASS Rules 2024

2024 MASS Mid Atlantic And Dillon Motor Speedway Street Stock Rules

  • 1. Minimum 4-point roll cage mandatory, two points in front of the driver and two behind. Mandatory at least 4 door bars on left side, 3 door bars on right side. Cage must be welded in a professional manner and is subject to approval by tech personnel. Driver side window net is mandatory.
  • 2. Battery must be in a full closure box and be securely fastened in front of rear end or in driver’s department. Master On/Off switch easily accessible from driver’s window.
  • 3. A racing seat constructed of at least aluminum is mandatory. Seat must be secured. Must be fastened to the roll cage or frame structure. An onboard fire extinguisher is recommended.
  • 4. All safety belts must be mounted per manufacturers’ recommendations. The belts should be a minimum of a five-point harness and must be in good condition. Restraint system must be securely attached to roll cage structure.
  • 5. Car must have a front and rear firewall between the driver, engine compartment, and fuel cell area. Minimum height 10” from ground. Any car that does not have an OEM floorboard will be assessed 50lbs.
  • 6. A made for racing fuel cell with foam is recommended. (maximum 22 gallons) gasoline only, no additives. Fuel line must run through steel tubing if running through driver’s compartment. If running under car must be securely fastened. All Cars must run 100 % Track Race Fuel or 100% Non Ethanol Pump Gas No Mixing of Gas or additives.
1. Mid Atlantic Street Stock Series Is Home To the Best Street Stock Drivers In The World. Participant must be at least 12 years of age and Radios will be permitted for use. No Convertibles, Station Wagons, or Pick- ups. All interior must be removed. All holes must be patched in firewalls and floor pads.
2. American Made Cars and the Wheel base must be within 1″ of factory specs, 102in minimum allowing 1inch grace for alignment. Any car that is not within 1″ of factory wheelbase specs will be allowed to compete with a 100 lb. weight penalty. Wheelbase must be within 1 inch of side to side. Camaros, Novas and Firebirds will be allowed but Must retain stock rear leaf spring suspension. Leaf spring suspension can have rear adjustable shackle plates allowed to raise or lower car since there is no screw jacks. A leaf spring car will be allowed adjustable lowering block to straighten rear end. A trailing arm car will be allowed eccentric or steel heims to be able to straighten rear end. Pinion wedges or adjustable top links allowed to adjust pinion angle. Chassis hookups must be OEM for make and model chassis. For any car in 2017 if your rear suspension chassis frame hookups are changed from stock OEM design you must add 50 lbs to total weight. This weight will increase at each successive race until fixed. Examples: multiple holes, panhard bar, adjustable panhard bar added third link etc, weight increase includes these items and will continue to increase each successive race until items are removed or reverted to OEM. Tech Man’s Decision.
3. 5″ Minimum Body, Frame and Chassis Height at Any Time When Officials Check! The 5-inch Height of Car Can Be Checked Immediately Coming Off Of Race Track In A Designated Marked Area On Pit Road. The Car Will Not Be Compressed By Tech Man.  If the Car Does Not Clear the 5″ Wheel the car is illegal when checked by an official. 3″ Minimum height for Oil Pan, Sway Bar, Headers. Maximum Rear Weight on All Cars 49 Percent Checked Full of Gas.
4. Bodies must be steel, absolutely stock appearing, no chopping or lowering of bodies in any way. Factory OEM roof must be used, No -49 Inch Late Model Fiberglass Roofs. Aftermarket Fiberglass repo roof allowed with weight penalty. The top of the rear quarters must be OEM and may be penalized with weight if not to keep bodies under control (weight determined by official). Aftermarket OEM replacement front fenders and lower quarters may be used. The hood, deck lid and doors may be aftermarket. Any Metal Rear deck must be securely fastened. Third generation Camaro’s are allowed in the series. No Current Aftermarket LM Body. All Bodies must be Tech Man approved. Maximum height for top of rear spoiler __ inches (TBD). Non-Approved Street Stock body is subject up to a 100# pound weight penalty or restrictor plate (Car Will Be Penalized in Quarters (Rear Quarters, Doors, Front Fender, Roof). If you think your body is marginal, please text a picture to Ron at 843-496-4792 or email a picture to ron@dillonmotorspeedway.com for a ruling before the race day. Any car that does not meet specifications will be required to add weight and/or restrictor plate. If car is too cheated up the street car will be allowed to race in another class at the speedway.
5. A maximum 5″ tall x 60″ wide spoiler will be allowed (300 max square inches). Factory spoilers size allowed. A hood scoop will be allowed. Rear tail must be enclosed with a stock appearing bumper cover. No right side windows. Vent Windows allowed 12-inch max.
6. Standard round air cleaner – no fresh air or induction systems allowed. No directing fresh air to the carburetor No flow control air cleaners allowed. Front of hood must be securely fastened.
7. 3150 lbs minimum weight for 602 crate engines, 3225lbs for 603 crate engines and 3150lbs for “Built Engines” with driver after race, 55% left side maximum, no fuel, water or oils may be added after the race to any cars. Maximum 49% Percent Rear Weight Checked With Car Filled With Gas. All Cars Maximum 55% Left Side. Declared weights must be displayed on top left corner of windshield or back of hood.
8. Automatic transmissions with stock OEM type working torque converter, min. 10”. No lock ups Straight Drive Clutches and pressure plates must remain OEM stock. No lightening allowed. Clutch pressure plate, disc, flywheel, and flywheel bolts must weigh 33 lbs. minimum.
9. Standard OEM production transmissions 3 or 4 speeds will be allowed to compete. All gears must work. No overdrive gears allowed. Must use a steel blow proof bell housing if using OEM stock type clutch. 7 ¼ or larger metallic clutch will be allowed with a 75lb weight penalty and may use a metal bell housing. Starters must mount in stock location. A hydraulic throw out bearing will be allowed.
10. Racing wheels only up to maximum 10”. NO softener or tire treatment of any kind. Scuffed 10″ Hoosier Track Tire. Tires for the 2020 MASS Season will be Scuff Hoosier TBD. Tire Sets will be Equally Graded Track Scuffed Tires will be drawn and will cost $160 complete set. Teams will be required to buy Tires (Scuff) at the track that will be Series branded! The marked Qualifying set (as Sold in Sets) will be the tires you start the race on and may be impounded! If you Change a flat you must install a Series Scuffed marked tire. The series will come by your pit before race time and approve a sixth tire in your pit as an extra side spare. If you have a Pit Stop you will be required to start at the tail end of the race field unless it is the halfway point. There will Limited fuel on Pit Road with 1 electric wrench and 1 jack. There will be a 10 lap rule in effect where all lead lap cars proceed to the front of the field. You must start the race on the tires you qualified on! If there is a caution near the halfway break race control may use it for the halfway if being used.
11. Frame must remain stock specs from front of steering box to center of rear-end housing or subject to weight penalty. Frame must be same dimensions from front to back (length and width). Frame and cage may be tied and reinforced together by rectangle, square or round tubing for safety. Front clip must be OEM and may be notched for fuel pump and oil pan clearance.
12. Cars must retain stock OEM spec parts. Lower A-frames must be in stock mounts and stock locations. Upper A-frame mounts may be altered. Tubular UPPER A-frames may be used. Unaltered Lower A-Frames must remain stock OEM and must be same length on Right Side and Left Side excluding Ball Joints and Bushings. (Lower A-frames, spindles, trailing arms, and steering components must remain stock OEM parts) Tie Rods may be Steel Sleeve with Steel Heims with metal spacers and or slots to work out your bump steer. Front hubs and rotors must be same size and in OEM location and not be lighter than OEM stock. A floater rear end will be allowed. OEM Limited Slip, OEM Open, Locked Up Spool, or Detroit Locker Allowed. No Gleason or Gear Driven Devices allowed. No cambered rear ends allowed (max .4 degrees). No travel limiting devices on suspension. No rear gear rule. Steel third members. Cars must have a complete steel firewall and floor pans. No boxed Interior. Sheet metal must be lower than driveshaft tunnel.
13. Maximum tread width for front and rear of car measured from outside to inside of tires at spindle height is 66 1/2”. Front sway bars must be stock type or Howe type 1.375 max. No rear sway bars allowed.
14. One steel shock or strut per wheel, $120 each claim rule. Any driver that finishes in the lead lap may claim. Track officials may refuse to allow claim. Claim can only be a forward claim no back claims. Claims must be made in Cash within 10 minutes of checkered flag. If a driver does not accept the claim the driver will be dqed which means no pay or points for that event. No Coil Binding of Springs, No Chassis Stops or Bumpstops. No Travel Limiting Devices on Suspension or Shocks. Ride Heights Can Be Checked At Any Time During The Event. Shocks On Car Will Be Time Limited To Return To Static Height By height check at any time.  No pushing down on car front or rear. Strut equipped cars may take guts out of struts and mount an external shock on car. No truck trailing arms allowed.
    Single metal piston brake calipers OEM Design allowed and all 4 brakes must work. Brake proportion valve and/or Brake Bias must be out of reach of the driver. Steel Driveshaft must be painted white with at least one driveshaft loop.
    Crate Engines: (see weight rules) Chevrolet 602 or 603 crate engine OEM specs only will be allowed to compete with a 500 Holley. Headers allowed No rear gear rule. All engines are Subject to complete tear down or crate engine exchange after race. GM Bolts Mean Nothing. 602 Crate engine must weigh 3150lbs. All cars left side maximum 55%. All Engines are Subject to tear down after race. MASS will use the same rules as Dillon Motor Speedway Protest Procedures
• Crate Engine must be used AS SUPPLIED from GM Manufacturer. OEM repair parts may be used from parts houses. This includes the valve covers, circle track oil pan and cast distributor supplied for make and model engine used AS SUPPLIED from GM Manufacturer. Example 602 parts must be on a 602 engine etc. These engines are subject to teardown procedures and legalities determined by tech committee. The staff at Dillon Motor Speedway and MASS Series has invested a lot of time and money to be “up to date” on these engines, therefore make sure the engine is legal.
• • Crate engines are designed to cut the cost of racing. Anyone found tampering with these
• engines will be fined up to $1000.00 for each offense and loss of championship points.
• • Crate Motor is a great application for Local Racing if the competitor will leave them alone. Run them as supplied from the factory to ensure legality. Any questions Contact Us
• MASS Series Reserves the right to claim any Crate Engine that competes in the series. DMS and MASS Owner Ron Barfield can trade a new Crate Engine of the same part number for the one in the race car at the completion of an event at any MASS Event! If the Claim is denied the Car Owner will be subject to penalty and a fine!
    ***All Crate Motors Must Pass The Yellow GM Crate Motor Inspection Guide. This Book is supplied to Racetracks For Teching Purposes. A copy of this yellow book is supplied at the GM Performance website with all the specs. All Engines will be teched by this tech manual whether the engine has the sealed bolts or not. Started in 2017 Any Crate Engine that has been opened up and changed from the way the engines was AS SUPPLIED from GM Manufacture will be required to add 75lbs. to total weight. If the motor is not by the yellow manual it is wrong and will be dqed. If you are claiming it is AS Supplied From GM Manufacture for the lightest weight,  if anything has been cut, replaced, grinded, wrong gasket, etc It will be dqed. If it has been torn apart and changed from AS SUPPLIED by GM Manufacture (but still legal) for any reason you must add 75 lbs.to total weight.
Built Engines (Section 2): 3150lbs for base built engine allowed to compete with a 350 Holley. Headers allowed. Contact Ron Barfield at 843-496-4792 if you have any questions on your built engine combination. We Will Work With Your Combination.
1. • Only standard production engines from manufacturer allowed. 350 cubic inch OEM stock
2. engine plus overbore. No high performance parts allowed unless listed below. Overbore
3. of .060 permitted. Any 6 cylinder engines contact speedway for requirements. 6 cylinder cars may compete but must weigh 2800lbs. 4 Cylinder Street Stock Body Cars will be allowed to compete by running the 4 Cylinder Mayhem Rules and weighing 1 pound per cc
4. • No polishing or coating any parts including inside of block. No electric fuel pumps
5. • OEM Stock or OEM replacement parts for OEM cubic inch including cylinder heads, pistons, crankshaft, and any 5.7 steel connecting rods only.
6. • Flat top or dish three ring pistons are permitted. Pistons may have min “two eyebrows”.
7. • Crankshaft with stock stroke must be retained. 50 lbs min weight. Crank journals may be ground for undersize bearings. No lightening or drilling. No other machine work will be permitted. Enlarged OEM oil pan permitted.
8. • OEM stock production steel heads only with OEM steel valve size and combustion required. • Piston must not extend above top of block.
9. • Four bolt-main blocks permitted. Engine must be in front of ball joints. Aftermarket pulleys allowed. Unaltered Edelebrock 2101 or 2116 or steel intake allowed on built engine. 602 GM Crate intake ok
HEADS and CAMSHAFT(Section 12)
• Stock production steel heads only. No angle plug heads. Vortec heads must have a restrictor plate on a .450-.480 cam lift built vortec head engine with a max 1.357 spacer plate adapter with a no bevel. No restrictor plate required on low lift camshaft (.425 and under). Stock Replacement (SR) head will be allowed with a 100 pound penalty.
• NO modifications, no porting or polishing. No grinding of any kind. Standard 3 angle valve job allowed.
• Chev 70cc min; Ford (Clev) 68cc; Ford (Win) 58cc; Chrysler 68cc min. Chev Vortec 60 cc min
• OEM valve size for cylinder head required. Steel valves required. Any Chev head with cc’s that are below minimums or any valves bigger than 1.94/1.50 will be required to add a 100 pounds or 50 pounds for each. Tech Man may approve other combos with a weight penalty
• Cam and lifters solid or hydraulic with a maximum lift of Chev .480, Ford .512, Dodge .500. Lift will be measured at the valve retainer as run in the race. Any Ratio Rocker to achieve max lift is ok! Any Cam that lifts under .450 or over .480 is eligible for a weight break/carb or weight penalty at tech discretion.
• Stock OEM valve spring and retainers. Aftermarket rocker arms allowed. Poly- locks ok.
Studs may be pinned, screw-in studs and guide plates permitted. Valves must be steel.
• Valve size maximum: Chevrolet 1.94 intake 1.50 exhaust
Ford Cleveland 2.05 intake 1.65 exhaust
Ford Windsor 1.89 intake 1.60 exhaust
Chrysler 1.90 intake 1.60 exhaust
Any engine that does not conform to the above engine rules may be able to add weight and/or restrictor plate to be able to race. Tech Mans decision is FINAL.
    Exhaust must not be over three and half inches in diameter (max 3 1/2” diameters) that may exit from underneath the car. Exhaust may exit the right or left side of the car for safety. No Dr. Gas Or Merge Collectors. If Exhaust exits out the door it must be lower than driveshaft tunnel with as minimal floor trimming as possible. Exhaust must be covered in 24 gauge steel. No Header wrapping.
    A HEI style aftermarket distributor may be used and may be locked for the built motor. Coil and module must remain in distributor. No digital tacs, No 16v systems. No traction controlled devices of any kind will be allowed. Water only, no antifreeze No electric fuel pumps.  A Full Steel Engine Firewall may be notched and plated or moved back to allow engine to be located. Excessive Moving or Cutting could result in weight penalty by tech official
    1. Engines may be interchanged from one body manufacturer to another. Full Steel Firewall may be notched or moved for motor placement and room by must be acceptable to tech official.
    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
2. • Holley 2300 2bbl carburetor model #7448 “350”allowed “built” motor or crate motor.
3. Holley 2300 2bbl carburetor model #4412 “500” allowed on “crate” motor only.
4. • No alterations except choke hardware may be removed and all vacuum ports must be plugged.
5. • No polishing, grinding, or machine work allowed on any part of carburetor.
6. • Only stock passenger car OEM boosters allowed. No modifications allowed. No bevels
7. • Base plate must not be altered in shape or size. The Holley 500 and 350 must have choke horn. The new Holley Ultra 500 with no choke horn is not allowed. (released in 2015)
8. • Any attempt to pull outside air other than through the venturi is not permitted.
    1. Crate Engines allowed with 500 Holley two barrel. Choke horn must remain, choke mechanism may be removed. A 3/4″ Inch Centered Non Adjustable Aluminum Carburetor Spacer plate with 2 gaskets (.065 thick each) (1 on each side of spacer) allowed. Carb Spacer must be aluminum straight cut no bevel.  No Coated or Anodized Spacers allowed. Air Cleaner base must not be above choke horn.
    2. Built Engines allowed with a 350 Holley two barrel. Choke Horn must remain, choke mechanism may be removed. A 3/4″ Inch Centered Aluminum Carburetor Spacer plate with 2 gaskets (.065 thick each) (1 on each side of spacer) allowed. Carb spacer must be aluminum. No Coated or Anodized Spacers allowed. Air Cleaner base must not be above choke horn.
1. All body parts must be securely fastened. Any body parts that appear to be loose or not securely fastened will be black-flagged
    1. Any car that does not conform to any of the above rules may be required to add or lose weight and/or restrictor plate determined by the tech committee. MASS officials may use professional judgement for any infractions for a competitive race program.
    1. Numbers can now be guaranteed for the race. You may request your numbers immediately by sending your registration and fee. Numbers to be guaranteed will be first come, first serve.
    1. No entry refunds. Promoter has the right to reject any entry or car from competing. Rules are subject to change at officials’ discretions and weight penalties may be added for rule infractions.
    1. A finishing order will be posted at the tech area after post race inspections are completed. Competitors will have 15 minutes after the posting to protest the finishing order. After 15 minutes, the finishing order will be official and no changes will be made.
1. Base weight 3150lbs, 55% left side maximum checked after race. Fuel, water, or oils may be added to any cars after the race. Designated weight must be declared on bottom left windshield.
Base weight for 602 crate engines – 3150 lbs. 55% max left side weight. 55% max left side weight
 Base weight for “Built Engines”– 3150 lbs. 55% max left side weight
    Maximum rear weight 49 percent will be checked full of gas.
    Any Crate Motor that has been opened up and cut must add 75 lbs. to total weight
Any Car that does not conform to any of the above rules may be required to add or lose weight and/or restrictor plate determined by the tech committee. MASS Series or DMS officials may use professional judgment for any infractions for a competitive race program. Tech man’s Decision on a fair race program is final decision.
    You are responsible for the weight of your car, make sure you understand the rules and make your car the correct weight for after the race.
We reserve the right to change or adjust the rules at any time to enhance competition and car counts.
    ***THE MASS Series will use the same protest procedures as Dillon Motor Speedway. The costs will be the same, time frame and the procedures. *** Please Read!
Any questions on the MASS or DMS events contact Ron Barfield at 843-496-4792, or Race Day MASS Tech Official Ronnie Barfield at 843-319-9797. Officials Decisions are final.