General Rules


  1. Any questions, Rusty at 307-789-8556.  If these rules or a phone call to us does not say you can do it THEN DON’T. We can’t stress enough to call first.
  2. Any American make car can run with the following exceptions; No 2003 or newer FoMoCo frames, No 1973 or older Chrysler Imperials or Imperial sub-frames, 4×4’s, ambulance, hearses, trucks, limousines, etc…
  3. All drivers and pit crew must sign the driver/waiver paperwork or they will not drive in the event.
  4. Driver must wear a seat belt, helmet, FIRE SUIT JACKET (no more exceptions to the fire jacket rule).
  5. All Drivers and ONE crew member must attend the drivers meeting.
  6. No hot rodding in the pits, keep it at an idle. This will be the quickest way to be DISQUALIFIED.
  7. No drivers are allowed alcohol – period. If you are wearing a driver’s band and drinking any form of Alcohol -YOU (if teamevent AND YOUR TEAM) WILL BE DISQUALIFIED.
  8. Cars will be re-inspected before any prize money is paid out. The cars will be re-inspected by the Stirrin Dirt Derby staffonly. Everyone else will stay back until cars are deemed to be legal.

Car Preparation:

  1. All cars must be stock, unless modification is stated in the rules.
  2. All glass, plastic, chrome, and interior must be removed from car before arriving to the derby.
  3. All trailer hitches and braces must be removed.
  4. 105” maximum  wheelbase no four wheel drive. Use general rules for building
  5. You must have a number in Bright colors on each front door and must have a 15”x15” sign on the roof of your car with carnumber on it for judging and recognition of the car. You cannot use the roof sign to strengthen the car.
  6. All cars must have working brakes when you cross the ramp. If the car is not able to exhibit the ability to stop it will not beinspected.
  7. NO welding other than what is mentioned in this set of rules. If your car is found with any weld, other than what is allowed,and you refuse to fix it to the judge’s satisfaction, you and your car or team will not run!!
  8. You must have an air cleaner over the carburetor all at times during the event.
  9. Anything can be removed; NOTHING can be added. Other than what is specified in the rules

Frame Shortening
1. You may shorten the front frame on the front frame only. You may cut the frame off flush with the front edge of the body

mount hole, or up to the core support if there is no body mount hole. Lower core support must remain in its factory position whether welded or bolted. If it is a weld on mount leave the remaining portion of the body mount in place. If you remove the body mount completely or relocate it you will not run.

Frame Welding

  1. No re-welding of any factory seams is allowed.
  2. Rust Repair – Call before fixing any rust on the frame. The rust can be cut out a piece cut exactly to the hole size may be buttwelded in.
  3. No changing or doubling of the rear package tray.

9. After Market parts that are allowed: Metal Gas tank, Transmission cooler, fuel cooler, brake & gas pedal, shifter,

battery box, steering column up to the steering box, drive line, driveline brake, lower saddle cradle, motor,

transmission bells, rear ends (see rear end section), seat and seat belt.

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Frame Shaping

  1. You may COLD tilt the frame at the transmission cross member area only. You must adhere to the bumper rule height.
  2. You may notch the frame in the trunk area only.
  3. No frame shaping is allowed.
  4. No Fresh Paint or Undercoating on the frames at all.

If your frame is rusted through, call for instructions on how to the fix the rust hole. DO NOT FIX IT WITHOUT CALLING AND EXPECT US TO ALLOW YOU TO RUN IT. If you have to re-stub your frame do so under the front doors but do not support the splice with the cross member. No ’03 and newer rear frames attached to ’02 and older front frames.

Rear Suspension:

  1. Suspension must be stock components and working. No coil spring to leaf conversions or vice versa.
  2. Leaf springs must be stock and made of stock spring material, with a 1”stagger and no springs can be as long as the mainleaf. You can only have a total of 9 leaf springs per side no thicker than 3/8″ thick and no wider than 2 3⁄4” wide. The main leaf must be the top spring in the spring pack and leaf springs must go down from longest to shortest in minimum 1” stagger. You can re-clamp springs, 4 clamps per spring pack, two on each side of axle. Homemade clamps can’t exceed 2”x4”x1/4”. No duct taping leaf springs.
  3. You can change coil springs to a stiffer spring, you can double the rear springs (they may be tied together in no more than two spots, do not weld them together), or put spacers in coil springs to get your height, do not raise the suspension any other ways except what is listed above. Coil springs may be welded to the axle only.
  4. You may use 3/8” chain around your axle to the frame hump with one wrap (this may go thru the sheet metal directly above the hump), links may not be welded.
  5. You may weld leaf spring mounting brackets to prevent them from becoming unbolted.
  6. No other means other than tires and springs and spring spacers may be used to raise the cars suspension.

Rear Ends:

  1. Use rear end of choice, but must be no more than 5 lugs. Back braces are welcome. Braces may not extend more than 4 1/2” on the outer 10” of a stock size axle tube or 10” on the remaining housing.
  2. You can tilt rear end if you wish. Welded, spool or posi-track allowed
  3. No axle savers.
  4. Rear end control arms can be reinforced. They must start from a stock set but can be reinforced. They must attach in stockconfiguration for the suspension setup you are using. You must use the factory brackets that came with the car you arerunning. No Relocating brackets on the frame or package tray.
  5. Watts-Conversion’s are not allowed

Front Suspension/Steering:

  1. Suspension must be stock components and working.
  2. Tie Rods and Ball Joints – Tie rod tubes must remain stock. Do not re-engineer the way the steering components mount to theframe. Only stock car replacement ball joints and tie rod ends are allowed; no pickup or van tie rod ends. No front suspension or steering may be reinforced with the exception of shortening a Tie rod in which case you may use no more than a 5” x 1” O.D. pipe sleeve or 5” x 1”x 1” angle to reassemble.
  3. A-Arms – A-arms may be welded, bolted or chained down but may not be reinforced. If welded it may only use up to a 2”x4”x1/8” thick strap. This strap must weld to the a-frame and cannot extend farther forward or backward than 1” past the widest part of the a-frame. If chained, only one wrap of 3/8 chain and it may not be welded anywhere. You may put older a- arms brackets on newer style Fords only, but do it cleanly. If you convert a-arm mounts the bumper bracket will go off the original style mounting location or the new mount.
  4. Steering box – May be interchanged but must remain a stock box for a car that is legal in the class you are running. Pitman arms must remain stock or stock replacement.
  5. Idler Arm – Idler arm must remain stock or interchanged for an idler arm for that is off a car that is legal in the class you are running.
  6. Hubs – Must remain stock for the spindle you are using, no aftermarket spindles, hubs or rotors. Brake calipers must remain stock for the stock spindles.
  7. Spindles – must be stock for a car that is legal in the class you are running, with no modifications.


1. No split rims, studded tires, or Duals.

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  1. Stock Rims only, no bead locks or reinforcing of the rim is allowed.
  2. You may on the outside rim lip add a piece of 1⁄2” rolled steel welded to the exterior lip only. 8 inch wheel center are allowed.No other reinforcements
  3. Valve stem protectors allowed. Wheel weights must be removed.
  4. All cars must be able to demonstrate the ability to stop at any time. If your brakes do not work, you will not compete.
  5. You may not change tires after inspection without officials consent.


The intention of this rule is to allow you to mount the bumpers in such a way that they are less likely to fall off. Upon inspection if it is determined that you have exceeded the intention of the rule you will be given the opportunity to correct it in order to compete, if you are not willing to correct it you will be disqualified. Officials have final say.

  1. No loaded bumpers may be used.
  2. Bumpers are interchangeable unless welding a non-compression type bumper to the body (see below).
  3. Stock O.E.M. bumpers off of passenger cars may be used or a Maximum 5” by 5” by Maximum 3/16” SQUARE tube maybe used, but must be open ended and straight. They cannot extend more than 10” from the outside of the frame. No skinningor additional metal may be added to the tube except small plates to mount if needed. No manufactured bumpers are allowed
  4. Bumpers may be flipped.
  5. Bumpers may be cut so they do not smash into the tires during the event.
  6. No chrome may be welded to the body if using compression style bumpers.
  7. Chrome of bumpers may be welded to the inner beam of the compression bumper only. No additional material may be added.
  8. Non compressions factory bumpers for that year of car may be welded to the body. Non compression bumpers may bewelded to the outside body only. (Note: Hood must be able to open).
  9. No more than one set of bumper brackets may be used. You can weld bumper brackets or towers to the frame. You can weldbumper brackets and shocks to the bumper. You can weld shocks to shock towers. You can collapse shocks, and you can boltthe shocks to the towers with 1⁄2” bolt or less, and it must be done vertically.
  10. No brackets or shock tubes are allowed to extend any further back than the first 10 inches of the frame.
  11. Instead of using bumper brackets you are allowed to use 1- 4” wide x 3/8” thick strap extending from your bumper down oneside of the frame and cannot extend any further back than the first 10” of the frame. You are also allowed to wrap this strap around the front of the frame 4” to create an “L” shape this is to give you enough material to weld your bumper to the strap. Plate may be formed but it cannot double at any point. Do not abuse this rule you will cut it.
  12. Bumper height not to exceed 18” to the bottom of the bumper to the ground and must be a minimum of 12” from the ground to the bottom of the bumper or frame. Bumpers must be in stock location.
  13. There are 3ways of “strapping your bumper on:
    1. Front and rear bumpers may have 4 loops of wire or one loop of no bigger than 3/8” chain from radiatorsupport/trunk lid or deck to bumper (not frame). These cannot be placed in front of the radiator.
    2. You may have 2 Front and 2 rear bumper straps that can be no larger than 36” x 2” x 1/4”thick. Up to 8” may bewelded to the body and the bumper.
  14. If using an aluminum beam bumper you may weld your front straps around and to the bottom of the frame or bumperbrackets. No more than 3” of strap may be welded or connected to the first 3 inches of the frame.
  15. Straps may have a hole burned thru it and be placed over the bolt over core support all thread bolt
  16. The bumper must be completely in front of the frame rails. No part of the bumper may extend back past the front most part ofthe frame rails.


  1. Motor – Use motor of choice, motor must be in stock location within reason approx 5 inches
  2. Frame Engine Cross Member – You are allowed to 6”x6” plates on the frame engine saddle to attach your engine mounts to.
  3. Lower Cradles are allowed but must attach to a factory style engine mount, with rubber bushing, attached to frame. Thefactory engine mounts are the only way of tying the motor down.
  4. Distributor Protectors are not allowed.
  5. Mid Plates are not allowed
  6. The following items are not allowed: Pulley Protectors, Transmission Brace, transmission protectors, after market tail shaftcones or Skid Plate.
  7. You may run an aftermarket bell housing but no other modifications may be to transmission. You may have a spacer in- between the motor and the bell housing, it must not exceed the shape of the transmission mounting pattern on the motor.
  8. You are allowed to bolt Transmission down to the cross member using factory transmission bolt holes near the tail shaft or chain it to the cross member.
  9. Transmission Cross Member -You must run the transmission cross member in the stock location for the car you are building. If using a tube you can weld 2” angle iron no thicker than 1/4”, no longer than 8” to the side of the frame to support the cross

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member. You must remove the stock mount if you run the angle iron. If you replace the stock cross member it can be no larger than 2”x2” O.D.x1/4” tubing. The transmission cross member must be one piece and must be straight from side to side. The transmission cross member is the only method which the transmission may be tied in. A 3/8” inspection hole must be with 12” of center if using tubing.

Body Mounts:

  1. Body mount bolts to the frame can be replaced with 1/2” bolts.
  2. Body mounts can be replaced with steel or washers but must be 1” thick and have the same diameter as stock spacers.
  3. Bolts may extend through body and have up to a 2” washer on top, washers must be separate and cannot reinforce the frame.Bolts must be up inside of the frame. If you choose to use a body mount hole for you trunk ready bolt this does not have to be up inside frame, the plate can go on the bottom side of the frame and be no larger than 3”. If you choose to leave in the stock rubber pucks you must leave the metal cones inside the rubber puck. You must leave at least a 3⁄4 space if using the factory rubber spacer. Do not devise a way that enables you to suck them down tight.
  4. Radiator support mounts can be removed, and you can suck the radiator support down solid. (see Radiator rules)
  5. Absolutely no body mounts may be moved or added, do not shorten the front of your car and move back past the body mounthole as your car will not run.
  6. If you have to build core support spacers you may weld it either to the body or the frame mount, but only one side can bewelded. Core Support Spacers cannot exceed 3” square material. . The front frame must not be shortened to far that the 1” all thread must pass through the factory stamped hole. The all-thread may only be welded to the side of the frame in this location. Chrysler k-member cannot be altered.
  7. You may have up to 1” all-thread, it may go from the hood to the frame, but must go through the front body mounts, this may be welded to the frame after it passes through the body mount but may not be nutted underneath the body mount if it is welded. One per frame rail.
  8. 1” All-thread may go from the trunk lid to the frame or trunk pan, if it passes threw a body mount hole you must have a 1” spacer between the body and frame. One per frame rail

Body Shaping

1. Body line creasing is allowed on fenders and rear quarter panels, all fenders, quarter panels rear sheet metal above bumper must remain in vertical position. No collapsing or wedging of rear quarter panels and trunks or trunk lid.

Rust Repair

  1. You can patch rust holes in sheet metal with sheet metal only. Do not cut rust out; weld 2” beyond rust.
  2. No buffing or grinding frames or bodies except where welding is specifically allowed in these rules.


  1. You may weld your doors shut with nothing larger than 3” by 1/8” strap or 1⁄2” round stock and must follow the door seam.Do not overlap strap or you will cut the strap off. Or doors may be tied shut in six locations using 1⁄2” bolts no longer than 6”,3/8 Chain, or #9 wire. If we do not deem the car safe to compete you will add more fastening points.
  2. You may smash the inner and outer skin together of the window opening and weld them solid. You may use the same filler asin welding the door seems but no longer than the window opening per door.
  3. Driver’s door and driver’s side of front windshield may have “netting” for driver’s safety. NO other windows may have“netting.”
  4. You are allowed to add bracing to the exterior side of the driver’s door. This bracing must not stick any further out than 2”from the door, and may not have any sharp edges. You are also allowed to carry the bracing up to 6” past the exterior doorseam either forward or backward.
  5. You may cut wheel wells for tire clearance. Fenders may be bolted back together with 5 -3/8” bolts or less with 1.25”diameter washers. No rolling your fenders and welding them. If you wrap or fold your fenders around the front of the coresupport do not exceed 4 – 3/8” bolts with 1.25” washers to bolt back to the core support of fender.
  6. Wagons must remove all rear decking and seat components. All other rules above must be followed.

Radiators, radiator supports:

  1. Only OEM style passenger car radiators may be used. Aluminum racing radiators of the same style may be used.
  2. Radiator must be attached to the core support. Radiators may be mounted in such a way to hold the radiator in place, notstrengthen the core support. For mounting radiators you may use up to 4 – 1/2” all thread. This may pass thru the bottom of the core support. This must not pass thru upper core support. It may be attached to a 2”x 6” 1/8” flat steel and must be welded

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to the core support they must be outside the fan. Or if welding radiator in place you may use four 1” welds, one per corner.

No added metal may be used to mount the radiator.

  1. No radiator guards allowed or foam may be used.
  2. You may not add cooling capacity. No supplemental cooling devices allowed (electric fans are allowed).
  3. If the arena allows, engine coolants may be used.
  4. Radiator loops may be used.
  5. Front core support cannot be moved back from its factory location. It must stay bolted to the fenders the same way that itcame from the factory.
  6. You may have up to 1” all-thread, it may go from the hood to the frame, but must go through the front body mounts, this maybe welded to the frame after it passes through the body mount but may not be nutted underneath the body mount if it iswelded.
  7. Radiator core support seam welding is NOT allowed.
  8. Radiator supports may not be welded to the frame, bumper brackets, bumpers or anything else.
  9. If using a condenser to protect the radiator, it may be tie wired to the core support only.
  10. NoFOAMfillcanbeused.

CAGES & DOOR BARS: SEE Diagram last page

  1. All cage material must be no larger than 6” O.D., unless specified for a specific rule smaller. It must also be a minimum of 4” off the floor everywhere except the down legs going straight down. No cage material may be within 6” of the firewall and be a minimum of 4” off the transmission tunnel. All bars must be straight.
  2. You may weld a bar behind the seat from doorpost to doorpost, it can be an X do not connect directly to frame, and you may also have a single bar (with no extensions), across your dash area to replace your dash. Side door bars may not go past the front dash or rear seat bar. End plates are mandatory with a max of 10”x10”, end plates must be a minimum of 2” larger than the bar being used.
  3. You may run a bar connecting the dash bar and seat bar inside of the front doors only.
  4. You may weld two down bars from the cage to the floor pan or frame vertically to protect batteries and your feet. Thesedown bars must remain behind the inside door seem and may only be welded to the floor sheet metal or top side of the frame,these bars cannot not exceed 2”x3”.
  5. Back of seat cage cross bar, including roll bar has to be placed above the rear side of the foot well kick up. You may weldtwo down bars from the rear seat bar to the floor pan or frame vertically. These down bars may only be welded to the floorsheet metal or top side of the frame. These bars cannot not exceed 2”x3”.
  6. Mopars are allowed to run a 1” bolt with a 5″ plate on both sides (frame and body) in the front most frame hole in the rearframe. You are then allowed to weld a Down bar from the door bar and weld to the top of this plate. It can be a maximum of 2×3” square tubing. All Mopar cage material must be 5” forward from the center of this body mount hole other than the kicker explained prior. Some cars have a very tight passenger compartment and you may need to run the halo through the small back window or thru the roof, call first.
  7. You must have a roll loop/Halo behind the seat, above the rear seat bar, this may extend to the floor as your rear seat down bar following rule 5 or 6.
  8. You may also weld a steering column to the cage.
  9. Gas Tank Protector – You must run a gas tank protector. It cannot attach to anything other than your cage. It must be centeredbetween your frame humps. It cannot exceed 24” wide. It can angle in from your roll over protection. It must be a full 4” away from rear sheet metal, which cannot be removed. The bracing must be 4” above all floor sheet metal, which cannot be removed, measured from the highest flat area of the floor in the rear seat area.

Hood and Trunk:

  1. Be prepared to remove your hood if the inspectors deem it necessary before or after the event.
  2. Trunk Lid and Hood must be 100% in stock location and open for inspection or have a min 20” x 20” hole for inspection andfire access in the hood and hinge spring must be removed.
  3. Any holes in hood may be bolted back together with 3/8” or less bolts and 1.25” diameter washer no more than a total of 8bolts allowed to pinch the hood sheet metal back together. You may cut multiple holes but do not exceed the 8 bolts.
  4. You can fold hoods or trunk lid over. Trunk lids must be stock shape but may be folded in but keep it clean. Rear fenders seeBODY #1. No collapsing or wedging of rear quarter panels and trunks or trunk lid.
  5. You are allowed 8 spots to hold the hood and trunk on including the 1” all thread to the frame. (See radiator #8 & bodymount rule#7). All other tie down spots must be sheet metal to sheet metal only. A combination of the following four ways to secure the hood and trunk is allowed. You may mix and match the types of hood/trunk fastening, but only 2 fastening points per side of the hood/trunk may be used.

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  1. If bolting, the hood and trunk bolts may be no larger than 8”x 3⁄4” with two 6”x6”x1/4”square or 6” x1/4” round. washers per bolt, with the exception of the two core support bolts thru the frame.
  2. Chains, #9 wire or cables may be used to secure the hood and trunk, 3”x3”x1/4” plate on top of sheet metal and may be welded in place to the sheet metal only.

i. Chain and cable may be no larger than 3/8”. If excessive chain or cable is found, it will be cut. If using chain or cable it must be singled looped. Two wraps of #9 wire, 1⁄2” all thread 8” maximum length, or 3”8 chain may be used no attachment point may come in contact with the frame. All wraps must go the shortest route to tie the lid to the body.

c. If welding the hood you may use 6” inch lengths of round stock maximum 1⁄2” or 2” by 1⁄4” flat stock rod welded in the seam.

d. Two 6 inch lengths of 2” x 2” x 3/16”angle iron may be welded to the body only back to back and bolted together with two a 3/8” bolt. These cannot be welded across the seam.

Windshield Bars and Firewall:

  1. Firewall – You are allowed to lay the firewall flat by cutting reliefs and pounding flat. If you shape the firewall or weld it to reinforce it you will cut the firewall out anywhere it is deemed to be reinforced. If you add any metal to the firewall you will be loaded without the opportunity to fix it.
  2. Window Bars – For safety, all cars must have (2) windshield bars extending from the roof of the car to the firewall/dash, straps cannot be any larger than 3/8″x3″ flat strap. If and only if you remove the firewall/dash completely between the straps you are allowed to connect these two bars. The removed part must be completely removed and must be as wide as the vertical bars. The horizontal bars connecting the two vertical bars cannot be any larger than 3/8″x3″ straps. No more than 6″ of strap material allowed on the roof and no more than 6″ of strap material allowed on the firewall. Do not go over 6″ on roof or firewall or you will cut. Must be min of 16” off of the pillars.
  3. One rear windows bar placed off of the center of the roof. Bar may not be bigger than 24” long by 2” x 2” O.D. Bar may only be attached by welding directly to the sheet metal or with a mounting plate no bigger than 4” x 4” by 3/16” angle or plate on the roof, cowl, speaker deck or trunk. If using rear window bar in a Station Wagon tailgate windows are treated as a rear window, but must be mounted at the top of the tailgate, and the tailgate must be in original closed position.
  1. No wiring or chaining of any window openings.
  2. Window bars may not be attached to the halo bar or any cage components.

Fuel Tank, Oil Coolers, & Transmission Coolers :

  1. Original gas tanks must be removed.
  2. Only metal Marine type tank, metal fuel tank or derby type metal fuel tank is required.
  3. Place fuel cell behind driver’s seat or in the center of the car where the back seat use to be. Must securely mounted behind thedriver’s seat with bolts, metal straps, or chain. No seat belts or pull tie straps may be used. No other source of gas inside thecar at all.
  4. 7 gallon (within reason) max tank maximum may be used
  5. Fuel lines must run inside the car, not under the car along the frame. Fuel line must be inside a protective line with in theengine compartment.
  6. Tranny and fuel coolers are allowed. These coolers cannot be placed to reinforce the car. No bolts may extend through theframe to create a body mount.


  1. Electric fuel pumps are allowed. The on/off switch must be easily accessible and clearly marked with bright paint. An “E” will be attached rear pillar during Tech to Identify the Electric Fuel Pump.
  2. Automotive pump gas only, NO ALCOHOL TYPE FUEL MAY BE USED!


  1. Batteries must be moved to passenger front floorboard. They must be properly secured and covered, unless you are using a gel cell battery
  2. Battery box must be made out of metal! It must be bolted to the floor. Bolts may not go thru or around the frame. Seat belts or pull type tie downs may not be used.

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  1. Rusted out holes in your floor sheet metal may be patched where components will be mounted or for drivers safety with sheet metal only. You may not patch clean and solid floors.
  2. All body mounts must be visible.


Each driver will have to purchase 8 plates for frame repair. Plates will be stamped; stamp must be facing out word to see.

  1. 4 per frame rail may be used; of which, only 3 may be used in front of the transmission cross member per frame rail.
  2. Plates may be bent and cut but excess may not be used elsewhere.
  3. Plates and weld must be separated by 1”
  4. No other frame welding will be allowed! All other repairs made to the frame will be removed.
  5. You may patch any hole in the doors or floor of the car for SAFETY only. You must use sheet metal only. And your patchmay be only 2” larger than the hole you are patching.
  6. You may reinforce damaged steering components on pre run cars only using one piece of 1”by 1” by 1/8” angle, but youmust use factory type and strength parts.OVERALL SAFETY IS OUR GOAL AND WILL BE DETERMINED BY THE TRACK OFFICIALS!Sample Cage LayoutScreen Shot 2016-08-01 at 10.52.35 PM