​

2025 DLM rules

SECTION 1: Transponders 

​

1. MyLaps transponder required. 

2. Transponders are to be mounted on the right side of the car, between 12 and 15 inches rearward of the centerline of the rear axle, and no more than 18 inches above the track surface. 

3. Transponders must be mounted with an unobstructed view of the track surface (no metal underneath). 

4. It is the driver’s responsibility to be sure that their transponder is charged and functioning properly. If you have a question about whether your transponder is functioning properly, it is YOUR responsibility to ask track staff to check your transponder during hot laps, and track staff will make every reasonable effort to alert you to any issue with signal strength or charge. If a driver’s transponder ceases to work during the course of an event, the car will only be scored until the point that their transponder stops reading. Any driver caught improperly mounting their transponder in order to gain an advantage will have their finish position be disqualified from the event (including forfeiture of points and prize money. If you have a question regarding the mounting location of your transponder, it is your responsibility to verify it with speedway officials prior to competition. Cars equipped with scoring transponders may, or may not, be tracked for lap time purposes. TRANSPONDER MUST BE IN WORKING ORDER, ON THE CAR FROM PRACTICE THROUGH FEATURE, OR YOU MAY BE REMOVED FROM COMPETITION. Make sure your transponder is charged, your subscription is up to date, and firmware is updated. 

 

SECTION 2: Competing Models, Years, Appearance 

​​

  1. Open to any North American built car from 1965-2010.
  2. Camaros are allowed, leaf spring cars only. Must use stock front clip.Rear chassis may be replaced with 2”x3” .120 wall box tubing.
  3. No 3 link, panhard bar, or torque arm rear suspension.
  4. All unibody cars must have a minimum two inch by three inch sub-frame. The sub- frame must be no less than .120 wall thickness.
  5. Camaros must follow all other chassis rules.
  6. Minimum wheelbase is 108” for all cars. Wheel base will be determined by the centerline of the rear axle housing to the centerline of the front lower ball joint (grease fitting) at ride height. There will be 1⁄2” allowance for leading of the rear ends. NO tolerance beyond this rule.
  7. Frame must remain STOCK from front to rear. Frame behind rear suspension, center line of rear axle, may be replaced with 2×3 inch box tubing. Johnson Chassis metric frame, clip & components allowed. Other manufactured front clips and suspension parts may be allowed provided they are professionally built( i.e. Hamm or similar ) and approved by home track rules.
Johnson frames & Johnson clips MUST meet the lower points of the Johnson template.
 

SECTION 3: Body 

1. Stock appearing aftermarket bodies allowed (i.e. ABC, S2, LMSC, and ARP Muscle Car). Bodies must look like stock bodies. No wedge or dirt late model style bodies. No down force noses. 

2. Aftermarket bodies allowed: ABC (pre-Gen 6), LMSC, AR Street Stock/Sportsman, AR Muscle Car, S2 Sportsman. Other bodies may be allowed with DLM written approval. 

3. Steel, aluminum, fiberglass, and composite bodies allowed. 

4. Aftermarket bodies cannot be lower than their published spec measurements.

5. Minimum ground clearance of 3” (nose & rockers). 

6. Rear bumper cover required, No holes or cutting for air flow. 

7. Rear spoiler max width 60”, max height 6”. May not extend beyond the width of quarter panels.

8. Aftermarket bodies cannot subtract material from their body panels. 

9. Material may be added to the rocker panels and nose to get a 3” ground clearance.

10. Aftermarket bodies cannot have additions to rear lower quarter panels. 

11. Performance Bodies 2019 Street Stock Camaro, Mustang & Camry (2) piece plastic nose & tail are allowed. 

12. No roof or rear window spoilers, No passenger or driver windows, No window deflectors. Rear quarter windows and rear window allowed. 

13. No hole in hood for air cleaners. 

14. No cold air boxes permitted. 

15. Side bars allowed with no sharp edges. One bar only. Cars with bars that can "hook" will be asked to fix them. Side bars must be flush (tight) with the body. Door side bars or the door if not using a door side bar, must be a minimum mounted out to the end of the tire tread (recommend to the outside of the tire bulge). 

 

SECTION 4: Engine 

1. Maximum engine displacement as follows: • GENERAL MOTORS 350 CU. INCHES • FORD 351 CU. INCHES • MOPAR 360 CU. INCHES. All engine dimensions internal and external must remain OEM stock for manufacturer and make. No altering of any dimensions unless stated in rules below. • Maximum of .060 over bore 

2. Engine location. For all frames, maximum engine set back #1 spark plug hole in line with the lower ball joint center line. 

3. Intake manifolds allowed: Edelbrock Chevrolet 2101, 7101; Chevrolet Vortec 2116, 7116; Ford 351c 2750/7183, Ford 351w 2181/7181, Ford #M9424 C358; Chrysler 2176 or any duel plane non-air gap intake manifold with approval from DLM (picture and part# submitted for approval). No port work, no blending, no coatings. 

4. All engines must use flat top pistons or dish pistons. 

5. Stock OEM production block only. No racing blocks. Dart part #3116111 SHP is allowed. No over-decking blocks for stroker type pistons. 

6. Sportsman rods 5.7 length or 6.0 inch. 

7. Forged crankshaft legal. Minimum crankshaft weight is 48 lbs. Counterweights may not be altered in any way. No pendulum & No undercut counter weights. No gun drilled cranks. Normal balancing only. Crank shafts must be stock stroke for the block. Rod and main bearings must be stock size (will allow up to.050 for clean-up). 

8. Cylinder heads must be OEM production or World Products S/R # 42660 or # 42670. Chevrolet OEM #10239906 & #12558062 Vortec Heads allowed. The DART S/S Vortec  SBC Iron Cylinder Head, part number 10024370 may be used as a cylinder head for repair.  No boss Ford or Chrysler Hemi or Pontiac ram air heads allowed. Chevrolet Bow tie & Vortec Bowtie heads Not Allowed. 2.02 maximum intake valve and 1.6 maximum exhaust valves allowed. Cylinder heads cannot have any port work done. NO Titanium parts allowed anywhere on the engine. No crossbreeding of manufacturers’ parts allowed. Cast Iron heads only. No altered valve stem sizes. Ie: no 5/16 valve stems in chevy motors. 

9. Any hydraulic or solid camshaft permitted. 1.5 and/or 1.6 roller rockers allowed. No roller lifters. Stud girdles allowed. Camshaft bores MUST remain STOCK per manufacturer. Lifter diameters must remain stock for manufacturers block Chevy 0.843”, Ford 0.875”, Chrysler 0.904” Repair sleeves allowed for lifters, must match original OEM dimension. No mushroom lifters allowed. 

10. Only stock type or HEI ignition permitted. Rev limiters allowed: MSD Soft touch rev control 8728, MSD Circle track RPM Control 8727CT, and MDS Ignition module w/rev limiter 83647. 

11. Car must have a working self-starter. 

12. No battery within the driver's compartment. Battery must be 12 volts. One per car. 

13. Maximum compression ratio 10.0:1. To be checked with a DLM approved whistler. 

14. Pre-tech engines @ ambient temperature will be 10.0:1 no tolerance. Post-race engines will have an allowance to 10.2:1 for heat “NOT” any higher. Any reading that flickers to the next highest number will be viewed as being the higher number. 

15. ABSOLUTELY NO ENGINE PART CROSSBREEDING BETWEEN MANUFACTURERS 

16. Crate engines are subject to the same rules & inspections as the open engines. 

17. Inspection hole in oil pan recommended to allow borescope. Lack of an inspection hole may require teardown.

18. The ROC Dart head will be allowed for the DLM event, specific wording will be posted in the coming days

 

SECTION 5: Carburetor 

1. One stock unaltered two-barrel carburetor. Holley 500 Carburetor #4412 only. No HP carburetors 

2. Stock 4412 fuel bowls only. No H.P. or aftermarket. 

3. No billet, No aftermarket, No H.P. metering blocks. 

4. Only one solid Carburetor Spacer made of aluminum or phenolic plastic of a maximum height of one (1) inch permitted. Only one .075 maximum gasket per side. NO wedge shaped mounting surfaces, both top and bottom surfaces must be parallel. Spacer must have 2 holes maximum size 1.750 straight bore and match the base of the carburetor. No air flow modifications. No alterations allowed to the carburetor spacer. No beveling, tapering, grooving or flaring of port holes. Spacer may not be stepped or undercut. Unaltered Mr. Gasket Adapter kit #1933 is allowed. 

5. Air filter housing may be offset for clearance of the distributor only. No tubes, funnels or any other device which may control the flow of air is permitted inside the air filter housing or between the air filter housing and the carburetor. Max of (1) 14” x 4” air filter. 

 

SECTION 6: Exhaust System 

1. Street headers & Standard Crossover headers only. Maximum collector size 3". No merge collectors. 

2. Exhaust system may use H pipe or X pipe. 2. Exhaust pipes must extend under the car and exit behind the driver. 

3. Mufflers are mandatory. Maximum allowable noise decibel to be 95db. Maximum muffler inlet and outlet size is 3.5" (adapter from 3.0" to 3.5" is allowed). 

4. Maximum diameter exhaust pipe allowed 3”. Tail pipe maximum size is 3.0". 

5. Adjustable exhaust headers, try-y type, collector type, 180 degree, merge type, pyramid type, exhaust headers will NOT be permitted. 

 

SECTION 7: Transmission 

 

1. Only stock OE production manual transmissions are allowed. Three/Four speed standard transmissions are permitted. Aluminum or steel case only. No drop out clusters. No trick parts. 

2. Only stock OE production Two or Three speed automatics transmissions are allowed. 

3. No automatic direct drive setups 

4. Internal Parts must be OE stock parts, or stock replacement parts. 

5. Steel or Aluminum Bell housings permitted. 

6. Removal of gears permitted. (automatic or manual) 

7. Clutch must be a single disc (10.5 inch GM, 10 inch Ford) diameter min. Stock type flywheel. Clutch, pressure plate & flywheel 30lb minimum. No High performance ultra-light clutch. 

 

SECTION 8: Rear Axle & Rear Suspension 

1. GM 10 bolt 7.5 inch, GM 10 bolt 8.5 inch and Ford 9 inch rear ends allowed. Full floater rear ends allowed, Locked rear ends only. No ratchets, gold track, Gleason’s or Detroit Lockers allowed. Steel spools only. 

2. All rear ends must be a leaf spring or four link suspension. Adjustable rear upper & lower control arms allowed. Rear arms stock length +/- 1.00”. NO truck arm style arms. 

3. No track bars or panhard bars. No connecting bars to the frame other than the four control arms.

4. Steel drive shafts only. 

5. Steel, rubber or mono ball bushings allowed. Heim ends are allowed in place of rear control arm bushings. Rear lower frame mount must remain stock. Rear lower housing mount must remain stock width. Heims must be centered in mounts. Rear upper control arm mounts may be moved and fabricated as long as you meet rule 3 above. 

6. Rear frames MUST go over the axle. No underslung frames allowed. 

7. Aftermarket axles allowed. 

 

SECTION 9: Front Suspension & Steering 

1. Stock type stamped steel or Johnson Chassis Lower control arms. 

2. No Rack & Pinion Steering. 

3. Racing springs may be used. Jacking bolts allowed. No coilover springs. No coilover eliminators. No bump stops. 

4. Stock OEM style sway bar or Howe Sway Bars allowed. No rear sway bar. No Spine Bars. 

5. A minimum of 5 inch frame ground clearance measured at the frame rail behind the front wheel and in front of the rear wheel. 

6. Tubular front upper control arms permitted. No Heims. 

7. Fabricated or stock upper control arm mounts are allowed. 

8. Spindle’s - GM on GM, Ford on Ford only. No racing spindles, no drop spindles. (i.e.: Impala spindles on a metric chassis is OK). Also allowed is Speedways GM metric 3-piece spindle part # 910-34501 (Short steering arm not allowed). 

9. No wide five hubs and/or spindles. 

10. Heim ends allowed for inner and outer tie rods only. 

 

SECTION 10: Shocks 

1. Must be a mass produced steel body shock. 

2. Shock must run stock box standard pistons. No adjustable rate piston you can fine tune. No modifying of the piston. Standard linear, digressive or COB. This means no additional bleeds or checks are allowed. No cross breeding of brand parts. 

3. No external schrader valves are allowed. Hyper nuts are allowed to repair or re-valve shock. 

4. Maximum rebound and/or compression shock valving allowed is a (12). Split valves are allowed. 

5. Shocks may be impounded after the race & sent out for testing. If the shock is found illegal, the shock will be forfeited and the racer disqualified. 

6. No bump stops, no packer shims, no bump springs, no bump rubbers & no internal modifications of shock to limit travel. 

7. Approved 2024 DLM shock brand & series: 

a) Bilstein SL Series. 

b) Bilstein SZ Series. 

c) Bilstein SLS Series. 

d) QA1 51 Series. 

e) QA1 26 Series 

f) Pro WB Series. 

g) Pro TA Series. 

h) Afco 12 Series. 

i) Afco 19 Series. 

j) Afco 24 Series. 

k) Afco 147 Series. 

l) Integra 421 Series. 

1. Shocks other than listed must be approved by DLM officials.

 

SECTION 11: Brakes 

1. Aftermarket OEM Style single piston Calipers allowed (aluminum or cast iron). No Late Model, No Modified style calipers allowed. 

2. Brakes are mandatory on all four wheels and must be in 100% working order. 

3. Dual master cylinders & disk brakes on the front and/or rear are allowed.

 

SECTION 12: Wheels and Tires 

1. Hoosier 1070 is the official tire of the event.

2. Steel wheels must be used and have a maximum width of eight inches. Racing wheels only.

3. All wheels must be fifteen inches. 

4. Maximum width measured outside of tire at spindle height: 80 inches. No 0′′ offset wheels. 

5. Only Two new tire allowed for the event. New tires must be purchased from Oswego Speedway the day of the event. Used tires will be available from DLM stock,.

6. No soaking or treating tires. Tires must meet durometer specs cold & hot. Tech reserves the right to remove any tire deemed suspicious. 

7. The tire policy for the GTR Super Stock Series will be as follows: All new (Hoosier 1070s) tires used in competition must be purchased from Oswego Speedway. New tires will be scanned and registered at purchase. Teams can purchase six new tires on or before the 6/14 race. Two of those tires must stay at the track until the next event. If you have one new tire still held at Oswego Speedway after 8/2, that tire will be allowed as your 3rd new tire at the DLM Teams that did not purchase tires for the 6/14 race can buy two new tires for the 8/2 race. Those two tires will be run throughout the entire 8/2 event. Teams that did not register as a “GTR SSS commitment car” can buy two new tires at the DLM event. Teams (commitment cars) that have raced in both previous races can purchase an additional (third) new tire as a reward for attendance. The only new tires allowed for use at the DLM will be purchased on the day of the DLM on 9/29 [see note above regarding 3rd new tire. Used tires can only be purchased at each race event. All used tires must be inspected, scanned, and registered before use. Four is the maximum number of used tires a team can have registered per car. There is no swapping of used tires between cars or teams. Damaged tires may be replaced at the discretion of series officials Tires will be marked before the heat race and must be run in the feature. Tires will be scanned after the feature. Any unregistered tire will result in immediate disqualification.

 

SECTION 13: Fuel & Fuel Cell 

1. All cars must have a fuel cell, 22 gallons maximum, must be in an enclosed steel container. Fuel cell must be no lower than the centerline of the rear axle housing with the car at ride height. 

2. Fuel rule: Sunoco / VP110 Standard Race Fuel only or 91 octane non ethanol pump gas only. 

3. Fuel shut off clearly marked in reach of the driver. 

​

SECTION 14: Weight 

1. Weight of all cars: 56% max left side, 3150 lbs. minimum with driver in seat, before & after the race with no allowance for fuel or fluids. Weight must be secured with a minimum of a ½” bolt, painted white, and bear the car number.

 

SECTION 15: Safety/General 

1. For races that include pre-race inspections, cars must be in the inspection line during posted times. Failure to be on time will prohibit cars from racing in that event. 

2. Racecar construction & driver safety equipment: Participating drivers must comply with all safety regulations of any and all participating tracks. All drivers are responsible for reading and complying with all safety regulations. Any track safety crew has the right to inspect and require a modification to comply with all safety codes. 

3. All cars must have a working fire extinguisher and fuel shut off in easy reach of the driver. 

4. Radiator must have an overflow can, one gallon minimum that must overflow to the bottom right of the windshield.

5. Oil coolers and transmission coolers are allowed. 

6. No Traction Control Devices. No electronic control devices. 

7. All roll bars, side bars, or other protrusions that drivers may come into contact with must be properly padded. Roll bar padding must be approved by officials. 

8. Throttle-mechanical linkage only with double return spring.

9. Seats must have on both sides rib supports, shoulder supports and head supports ( full containment seats are highly recommended).

10. Head and neck restraint devices are mandatory, no donut rings allowed.

11. Fire suits and other safety equipment will follow the Oswego speedway safety guidelines

12. Provisions may be made for home track rules on a case by case basis. Please contact a DLM official for clarification of any concerns.

​
 

SECTION 16: Tech 

1. Following each heat, b main and or feature race, the top five (5) finishing cars will proceed to the scales for weighing unless notified by officials. Wheel marks may be checked at this time. 

2. Following all feature events, the top five (5) finishing cars will proceed directly to a designated area for post race inspection. 

3. Prior to any race, both rear wheels will be marked with tape or paint line for a “locker check”. It is the driver’s responsibility to ensure that rear wheels are marked. Failure to mark the wheels prior to a heat race will result in losing your heat finishing position. Any non marked cars competing in a feature race, will require their team to disassemble the rear end following the race for inspection of gears and spool; and shall result in a $100.00 fine. 

4. Mirrors: One (1) 2” round mirror is allowed on the driver side “a pillar” area. One (1) 7" X 3" interior mirror allowed. We will allow teams to tape a bigger mirror to required size. If a driver is accused of mirror blocking, officials will research it. The driver will get a warning and will be on the watch list. If a driver is found to be abusing the mirror after the warning they will lose it. 

5. Tech refusal is an automatic disqualification and suspension. Driver and car will be suspended until illegal part/s are removed from the car and inspected by DLM officials. Failure to turn over the illegal part will lead to a fine and/or suspension. Drivers that get disqualified are subject to a fine, point penalty, and/or suspension depending on severity. 

6. Protest rules: The protest must be discussed & submitted to the DLM race director 15 minutes prior to the feature starting. Must be written of what you specifically want checked. Protestor has to finish in the top 10 in order to protest. In the event of twin features, the car will be taken apart after the last feature. 

7. Engine in car protest rule: The protesters car and protestee’s car will both be checked. During inspection, tech has the right to visually check anything else in that area. The fee is $500.00. $175.00 of that is non-refundable. If the protestee is found legal he or she gets $325.00; if the car is found illegal the protester gets $325.00 back. 

8. Engine removed protest rule: If an engine has to be removed from the car from a protest the fee is $1,000.00. $300.00 of that is non-refundable. If the protestee is found legal they get $700.00; if the car is found illegal the protester gets $700.00 back. Time and place to be determined by the end of that night. 

9. Soft Protest rule: This protest does not cover the engine rules. Examples of what this protest covers: whistle, wheel base, frame height, engine placement, clutch, carburetor, wheel width, rear end locker check, etc. The protesters car and protestee’s car will both be checked. The fee is $200.00. $100.00 of that is non-refundable. If found legal the car being protested gets $100; if the car is found illegal the protester gets $100 back. 

10. Shock  claim rule: $900 for the set (only available to the top 5 finishers). The competing car in the position behind the car ahead can claim the shocks (example 2nd can claim 1st, 3rd can claim 2nd, 4th can claim 3rd and 5th can claim 4th.)

 

SECTION 17 Code of Conduct

1. DLM / GTR promotions will follow Oswego Speedway’s general rules section including code of conduct for teams before, during, and after the event.

​
 

Note: Anything not covered in these rules will be considered illegal if not exempted by DLM officials. For further information please contact event promoter Jody London at 585-313-9979. Final decisions regarding the legality of exemptions will be made the day of the event.