2021 LKQ Pick Your Part Pro Late Model Rules

IRWINDALE SPEEDWAY Pro Late Model Rules Printable

IRWINDALE SPEEDWAY Pro Late Model Rules – ½ mile

(Former “Irwindale Speedway Late Models”: See Rule 9)


Irwindale Speedway reserves the right to adjust the rules at any time in the interest of safety and maintaining an even playing field.


  1. BODY and CHASSIS – Any traditional late model type perimeter or straight rail chassis is allowed. Body must be a factory stock Five Star or AR pavement style body, body must be mounted in a stock manner as it was intended from the manufacturer, no extra panels may be used to extend the body in any way, hood must cover the air cleaner with no holes other than a small opening at the windshield for air to the carburetor, complete rear bumper cover must be used with no holes drilled in it, no extra material may be removed from the rear bumper cover, rear spoiler must be mounted in the stock location. Maximum quarter panel height is 34.5″.


No under body air deflectors or wings of any kind. Teams are allowed to mount two ½” tall roof rails running front to rear on the roof of the car, but these rails are not allowed to extend down the rear window or onto the deck lid. No passenger windows are allowed, maximum for the vent window along the top of the door will be 12 inches and must go 90 degrees from the top of the door up to the A-post. No fans, ducts or hoses to the rear brakes or tires, no holes or hoses are allowed through the interior sheet metal. Ride height rule; all cars must be able to get on and off the inspection scales without the use of any extra ramps or boards and the car must not drag on the scales, if your car drags on the scales you will not pass tech and will be forced to return to your pit area for corrections.


Rear Spoiler may be no wider than 60″ and no taller than 6 1/2″. Spoiler must be centered on the rear bumper cover and may not be offset in any direction. There may be NO forward support of any kind, no boxed ends or runners. No Gurney lip, or any type of wicker bill on the upper edge of the spoiler. It is mandatory that the Upper 2/3’s of the spoiler and the rear window of the car be made of “clear” lexan to enable other drivers to see through them.


  1. ENGINES – 602 CRATE ENGINE that have a straight rail chassis are to be a minimum of 2,875# total weight and a maximum of 60% left side weight. 602 crate engine cars that have a perimeter chassis are to be a minimum of 2,825# total weight and a maximum of 60% left side weight. Maximum RPM for the 602 crate engine is 6,200 and cars must run a 6,200 RPM chip from the track or you may use the FAST/Crane ignition box part # 6000-6700and coil part #730-0192. 602 engines must remain OEM from factory and must be either GM factory sealed break off bolt seals or new style GM factory seals. All crate engines may be removed for inspection at any time after an event, especially if they are the old style break off bolt seals. You may run after market valve springs but they must be the same spring pressures as OEM, you may run the approved aftermarket replacement distributer, you must run a mechanical fuel pump in the stock location, and you must run the stock oil pan and stock harmonic balancer.


The maximum engine set-back for the 602 crate engine is 6″ measured from the center of the forward most spark plug hole to the center of the upper ball joint on the same side.  Any single 4bbl carburetor allowed.


NOTE: All stock type steering box cars with stock type lower a-arms (cars without rack and pinion) with 5″ or bigger diameter springs on the front suspension will receive a 25 pound weight break.


  1. TIRES AND WHEELS – Tires are the Hoosier 8.0-15/970 treaded tire. ALL tires MUST be purchased from the track, and tires MAY NOT be cut, soaked or altered in any way. Any team wishing to run used tires must submit the tires for inspection and scanning prior to qualifying, note these used tires must have been purchased from Irwindale Speedway as well. Wheels must be steel and not exceed 8″ in width. Competitors must start the race on the tires they qualified with.



  1. SUSPENSION – Minimum wheel base is 101″, rear wheel drive cars only.  Any steel shock, all external parts must be steel (Aluminum rod end on the shaft end ok, and an aluminum thread in body cap on the shaft end is ok). One shock per wheel, no remote adjusters or reservoirs of any kind may be used on a shock. Aluminum shock body penalty 25#. REAR SUSPENSION – No fifth (5th) coil, torque arm or lift bar suspensions will be permitted. No bird cages of any kind (3 or 4 link). Trailing arms must mount to the rear end and chassis in a solid manner (heim allowed). No springs, sliders, rubber biscuits allowed on any of the rear trailing arms. Truck arm suspensions will be approved on a race by race basis. Any non-traditional rear suspension layouts will be approved on a race by race basis.


All cars will not exceed 79″ inch track width, it will be measured from the bulge outside to

outside of the front tires at the spindle height. No independent rear suspension.


  1. No traction control devices. Only one ignition box allowed, and ignition box will be mounted as far to the right side of the car as possible with the chip or RPM dial facing the right side. All wires to the

distributor must be run separately and not be part of a bigger wiring harness. All wiring must be sealed with no unplugged wires.


  1. FUEL – All cars must run the track fuel, the track spec fuel is Sunoco 110 Purple race fuel or Sunoco E-85R race fuel. Teams may also run stock Chevron 91 octane pump fuel with NO additives and NO mixing of fuels.


  1. Drive shaft, NO carbon fiber drive shafts allowed. Driveshaft must be painted white.


  1. SAFETY – Approved seat belts and double shoulder harness and a crotch strap is required, no older than five years. A full-face helmet required with a 2010 (recommended 2015) Snell sticker. SFI rated full driving suit and gloves for fire protection mandatory, SFI undergarments are recommended. Driver’s window must be equipped with a safety net and quick release latch of minimum size 22″ wide by 16″ high. Resilient padding must be installed anywhere the driver can reach on roll bars. Onboard charged Fire System Mandatory. Head and Neck Restraint System mandatory. All teams must have a fire extinguisher in their pit at all times. All cars must have a clearly marked electrical cut off switch easily accessible to the safety crew. Batteries must be securely mounted outside of the driver’s compartment. 1/16″ steel side plate in driver’s door is mandatory. Roll cage must be constructed of 1 3/4″ o.d. steel x.090 round tubing, the main frame and clips from the radiator area to behind the fuel cell must be made of steel, main frame must be minimum 2″x3″ rectangular steel.







  1. 2020 Irwindale Speedway Late Model is legal to run with the following:

2020 Rulebook Legal car must weigh minimum 2925# and max 58% left side weight.

*Maximum rear gear 4.71 must be spool or locker, steel 3rd member and solid axles.

*perimeter chassis       *stock type lower       *big spring (5.5” front / 5” rear minimum)

*vendor sealed yellow book 604 w/gauge legal 650 carb *Factory GM 604 deduct 15#

*Minimum 50# 2 speed transmission * 15” x 8” steel wheel *steel driveshaft 2.75” min

*Kern Open GM 604 Engine must run a 1” Governor restrictor plate with 1.00” inserts.

*steering box *7.25” clutch *twin tube shock- ARS or QA1 * minimum 10” fuel cell height

*no bump stop/coil binding/limiting travel*steel single piston brake calipers

*Maximum tread width 79” measured from outside of the bulge of tire to outside of tire at spindle height.



All cars must run a transponder mounted 12″ behind the rear axle.


  1. The following infractions will result in a BIG penalty which could include a huge fine, suspension or a LIFETIME ban from the series.


  1. Being caught with traction control.
  2. Bypassing the RPM limiting control device in any way.
  3. Altering the 602 crate engine under the seals in any way that is non OEM.
  4. Altering the Hoosier 970 tire, such as soaking the tire, or cutting the tire. Tires are to be a stock 970 tire.
  5. If you are caught cheating the fuel in any way, the fuel must be stock as provided by the manufacturer, and must not have ANY additives whatsoever.


Illegal components WILL be confiscated by Irwindale Speedway and become property of the speedway.


We reserve the right to adjust the rules at any time in the interest of safety and maintaining an even playing field.