Medium Rules (Main Event)

Medium build Rules (Main Event class)

NOTHING other than what is listed below is allowed

Follow general preparation, if a car is disqualified the Team is disqualified!

Officials decisions are FINAL!!!


Vehicles may be re-inspected at any time before, during or after the show


1- BUILD TO THE RULES! Don’t over build and expect to cut to the rules. If anything is added to the inside of the frame other than what is specified in the rules you will immediately fail inspection and not be allowed to compete.

2- Original Frame, Body, clip/dog house Suspension and parts must be used unless otherwise specified below

3- All glass, plastic and pot metal must be removed. Nothing may remain in the bottom of the trunk or doors. Rear seats in all cars must be removed.

4- All outer hardware must be removed – door handles, mirrors, chrome, moldings, screws and fiberglass.

5- Driver door must be padded on the inside.

6- Front seats must be securely bolted to the floor; however, these bolts may NOT go thru the frame! You must have a functioning seat belt. Seats must be mounted within 5 inches of original FRONT seat bolts.

7- All flammable materials must be removed from the car other than safety padding and the driver’s seat.

8- No adding weight to the vehicle, no packing, stuffing of frames, trunks, passenger doors or under floor decking.

9- All trailer hitches must be removed.

10- NO Ambulances, Hearses, Sedagons, or Limousines allowed

11- Do not paint the body inside the car or paint the frame. If you do you will be sent to the car wash to power wash it all off before being inspected if your back in time.

12- After Market parts that are allowed:

13- 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, adapter plate for BOP transmission to Chevy block, seat and seat belt. None of these parts can come into contact or even get close to coming in contact with the frame or any Sheet metal we would consider reinforcement.

14-Post-race inspection will be thorough, and all these items will be re-inspected along with other areas that may be invisible in the initial inspection. Post-race inspection will include all the items looked at in initial inspection. So, you need to be right when you get here, right after the heat, right after the grudge and right after the feature.


SEE Diagram last page

  1. All cage material must be no larger than 6” O.D., unless specified for a specific rule. Drivers door bar only maybe any size for driver’s protection. 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 must weld a bar immediately behind the seat from door post to door post, it can be an X, however; do not connect it directly to frame. 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.
  3. You may weld two down bars from the cage to the floor pan or frame vertically to protect batteries and your feet. These down bars must remain behind the inside door seam and cannot not exceed 3”x3”.
  4. Back of seat cage cross bar, including roll bar must be placed above the rear side of the foot well kick up. You may weld or bolt to the sheet metal or frame two more down bars vertically below the rear seat bar. These bars cannot not exceed 3”x3”.
  5. You must have a Vertical roll loop/Halo or upright, it may not exceed 4″ O.D behind the seat located above the rear seat bar. This may extend to the floor as your rear seat down bars (see #4). Must be fastened to the roof in 2 locations at least 24” from center. if it leans towards the back window you will fix it at the track.
  6. Halo bars must be in a direct vertical line with the seat bar. They must be vertical.
  7. Upright post must have a max 10”x10” plate attached to the roof, welded or bolted in.
  8. Upright post must be mounted vertically and in such away it will not bend. (Ex. Gusseted)
  9. Gas Tank Protector – You may run a gas tank protector. It cannot attach to anything other than your seat bar. It must be centered between your frame humps. It cannot exceed 30” O.D. Wide, only one tube may be used, see diagram below. It must be a full 4” away from rear sheet metal, which cannot be removed or hammered back. The protector 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. One 12” gusset per side from the seat bar to the protector may be used. If you choose to run a gas tank cage, it may not be ANY MORE THAN the picture below and follow all cage to sheet metal distances listed above.
  10. In a wagon the rear gas tank protector can not be any farther from the rear seat bar than 30” O.D.

(3). Doors:

  1. Door seams must be welded using rolled rod no bigger than 1/2” or flat strap no bigger than 2” wide by 1/4” thick.
  2. You may smash the inner and outer skin together of the window opening and weld them solid. You may use the same filler as in welding the door seems but no longer than the window opening per door.
  3. Driver’s side of front windshield may have window fabric netting or chicken wire type material for driver’s safety. NO other windows may have netting.
  4. Tailgate on a station wagon is considered a door.

(4). Bumpers:

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. Only Stock O.E.M. bumpers off of passenger cars or square tubing may be used.
  2. A Maximum 5” by 5” by .”” SQUARE tube may be used but must be open ended and straight. They cannot extend more than 10” outside of the frame ends. No skinning or additional metal may be added to the tube except small plates to mount if needed.
  3. Bumper swaps are allowed, they may be flipped over, and the ends trimmed.
  4. No chrome may be welded to the body if using compression style bumpers.
  5. Compression style bumpers may be seam welded, but no metal added inside or outside.
  6. Non-compression bumpers may be welded to no more than 12 inches of the outside top side of body only using max of 2-inch x .” flat strap. Hood must be able to open so no welding to the front of the hood.
  7. One wrap of chain may be wrapped around the bumper, frame and core support (one wrap per side, see hood bolting rule). Or you may use up to two 2” by .” x 36” long flat strap from top side of sheet metal or top of core support to bumper. If using strap, may only be welded up to 8” on the top side of sheet metal or 4” on top of core support to the bumper. These may not cross but may be in front of radiator. Your 1” thread may pass through them.

7.Ways to mount a bumper:

You have 2 options for mounting the front or rear bumpers. Pick one only!

  1. Use the stock bumper bracket or brackets and shock tubes in the exact location and manner they were intended to be in from the factory and weld the first 10” of them measuring from the back of the bumper. No metal added. You may not swap bumper brackets and or shock tubes/beams.
  2. Remove ALL the factory brackets and shock tubes and in its place weld a 10” X 4” x .” flat plate to the side of the frame and weld it to the backside of the bumper. Your only hard nose options. If you need to square up the frame to get a good plane to weld the bumper to, do this by cutting off as little of the frame as needed. 80’s up Lincolns and Mercury’s may cut the front frame back to match the specs of a ford. If we think you have cut too much, we will compare you to other cars of your model at the derby and you’ll add to it.

8.You may use a 6” x 6” x .” plate at the end of the front frame rail to mount your bumper. On cars equipped with factory compression style bumpers you may compress the bumper shock tubes and weld them back but don’t touch anything beyond 10” with the welder. 80 and fomoco must maintain and utilize the original shock bolt hole.

(5). Frame:

  1. All body mounts “pucks” (rubber biscuit and cone) must be in place. You may not remove bolts and place washers on either side. Exceptions will be made for the all thread in the trunk and in the core support areas below.
  2. No seam welding, no frame swapping in any way.
  3. Frames may be notched or dimpled between the 2 rear frame mounts however do not touch the frame with a hammer anywhere else. Frame rust is to be handled on a case by case basis with officials. Email and you will be put in touch with one.
  4. Absolutely no cutting, tilting, welding, bending, adding to or altering the front frame in any way other than what is specified. THIS IS CAUSE FOR DISQULAIFICATION.

(6). Hoods

  1. Hoods must be able to be opened, or have a 30” by 30” minimum hole in the center of the hood if welded.
  2. Hoods may be secured with bolted angle iron (pieces of opposing angle iron each being welded to the hood and front fenders). Hood angle iron will be inspected within the following rules:
    1. Angle iron can only be welded to the SIDES of the hood. This is defined as driver and passenger sides.
    2. Hood angle iron can NOT exceed 18” TOTAL LENGTH per side of the hood. Drivers may split their

allowable 18” of angle iron as desired, but drivers can NOT use angle irons pieces shorter than 4″ in length (i.e. 5″ – 5″ – 8″ OR 6″ & 12″ OR 4″ – 6″ – 8″ and so on).

  1. Hood angle iron can NOT exceed 2” in height & width.
  2. Hood angle iron can NOT exceed 1/4” in thickness.
  3. A maximum of 2 bolts per set of angle iron are allowed, but can NOT exceed 1/2″ hardware.
  1. IN ADDITION TO bolted angle iron, (2) All-thread (one per side) with a maximum diameter of 1”may be used under the following stipulations:
    1. All-thread MUST be located immediately in front, behind, or pass through the radiator core support.
    2. All-thread can be welded or bolted to or through the front frame with no added metal.
    3. All-thread holes may be reinforced with plate material or large washers. Plate material can NOT exceed

4” x 4” square and 1/8″ thick. Washers can NOT exceed 4” diameter.

  1. ALTERNATIVELY, if drivers do not wish to use the bolted angle iron, (4) additional All-thread (two more per side) with a maximum diameter of 1”may be used under the following stipulations:
    1. All-thread can be welded or bolted to or through the frame with no added metal.
    2. All-thread must be within the engine compartment and can NOT touch, attach, or pass through firewall.
    3. All-thread holes may be reinforced with plate material or large washers. Plate material can NOT exceed 4” x 4” square and 1/8″ thick. Washers can NOT exceed 4” diameter.
  2. Welded Hoods The hood may be welded using ½” rod or 2” wide x 3/16” strap or smaller up to 6” long in up to 4 places on each side of the hood (passenger and driver side only, no welding the front of the hood). Provided that you have the minimum 30” x 30” inspection hole.
  3. Hoods must remain in ORIGINAL POSITIONS. They can be folded over at the radiator core support but can

NOT be slid forward. If folded, hoods can NOT be bolted or welded to bumper or radiator core support.

  1. Hoods can NOT be cut/sectioned with the front portion bolted or welded to fenders or radiator core support.
  2. Underhood support webbing can NOT be welded or bolted to the hood skin, except where cut for inspection / fire suppression hole.
  3. Hood skin can NOT be folded down to the inner fenders or radiator core support; however, hood skin can be folded to the underside of the hood up 4”and welded with no added metal or bolted with up to 3/8” hardware.


(7). Trunk and Body:

  1. Only quarter panels and fenders may be creased. All body panels must be in near original position vertically.
  2. The only Body rust repairs that will be allowed using sheet metal of the same thickness as the body are:
  3. The floor pan to “FIX” rust holes only no skinning of the entire floor. This applies to the driver seat & foot area, battery and gas tank mounting areas only. Nothing up the doglegs or excessive or it will be removed completely.
  4. Body rust repairs will also be allowed on the “pillars” only. A piece no bigger than 14” by 14” may be used. At least one 1” inspection holes must be in the sheet metal for inspection. Do not cover more than the rusted area (i.e. 4-inch rust hole does not need the full 14” piece).
  5. Hinge springs must be removed and two 10” holes need to be cut in the trunk for inspection.
  6. Trunk Lid and Hood must be 100% in stock location.
  7. All decking in wagons must be removed.
  8. Trunk may be tucked or dished. If your trunk lid is pushed down in the center must be at least 12 inches off trunk floor body at mount elevation.
  9. You may use up to 1” all-thread, with 3 nuts two 3” washers and one 5” washer (that must be on top of the hood and trunk lid) per all-thread. It may go through trunk lid to the frame, but must go through or down the side of the frame and welded to the frame only or a nut welded to the top of the frame. One per frame rail in the trunk. If you choose to use a body mount hole for your trunk all thread, this does not have to be up inside frame, a washer can go on the bottom side of the frame and be no larger than 3” O.D. x 1/4” thick. If you run your all thread through the body mount, you must still have 1” spacer between the body and the frame. Trunk deck maybe nutted and washered with a 3” washer.
  10. Choose one of the following ways to secure the trunk. This is allowed over and above the (2) 1” all thread.
  11. You may weld the trunk. 3 places on the drivers and passenger side with separate pieces of 6” inch lengths of . 1/2” rod welded in the seam or 2” wide by .3/16” thick flat stock.
  12. You may utilize 3 pieces of back-to-back 6” inch long, 2”x2” angle on the drivers and passenger side. These may be welded to the sheet metal but not across the seam and bolted together with a .” bolt.

(8). Engines Transmissions & Rear Ends:

  1. Engines may be swapped but must remain close to original position as possible. No cutting of the floor or tunnel to accommodate different motors: however, Transmission tunnel may be spit with a cutting wheel to relieve pressure.
  2. If you use Stock Engine mounting pads can be welded to the factory engine cradle only. You may weld one chain link to the engine frame cradle and use chain or cable to secure your motor. You may have one on the left and right side. No welding or bolting to the frame rails.
  3. A hole may be cut for the distributor. only the area directly behind the distributor above the tunnel seam, (if you do not have a tunnel seam pretend you do).
  4. If using an engine saddle cradle (see picture below), it may only be welded with 12” of weld or bolted to the factory engine cradle and not the frame and you may not use any strap, cable or chain. Two pieces of 2” x 2” x 6” square tube may be used as lower motor mounts.
  5. ANY direct bolt in 5 lug NON braced passenger car rear end may be used. you may add Factory style brackets close to the factory size, homemade or other. if determined to be adding structure they may be cut so keep within reason. No axle savers
  6. The only welding that will be allowed is welding to butt seam weld axle tube ends to make a bolt in axle work, add coil, control arm leaf mounts, coil spring perches and spider gears. No full float axles. You may weld the tube to the center housing, gears and axles may be changed but must be factory passenger car 5 lug pattern. If mounting a driveline break it MAY not brace the rear end in any way. Rear Brakes must work.
  7. Stock housing transmissions must be used. No Reid cases, steel bells, aluminum bolt on bells, steel tails, plated pans, skid plates or braces.
  8. A 2”X2”x.” thick tube may be used in place of the original stock transmission cross member. It must mount in the factory position for that car including Cadillacs and 70s fomoco products.

(9). Suspension and steering:

  1. Suspension must be stock components from a car legal in this class.
  2. Front a-arms and rear control arms may not be reinforced or modified or welded down. Must run the stock leaf pack for leaf cars. Original leaf spring clamps only. Exception lower rear control arms may be shortened by cutting them in half and overlapping them and seam welding only, no reinforcing.
  3. Tie rods and ball joints may be swapped out with big box store parts. No Joker, Ski, Wicked type parts and no welding, must bolt or press in.
  4. Coil springs may be welded to the axle only and may be doubled or shimmed.
  5. No other means other than tires and springs and spring spacers in the front suspension per rules may be used to raise the cars suspension. NOTHING can be inside the spring bucket other than the spring, spring and/or spacer may not be welded to the spring bucket.
  6. Chaining of humps is optional, if doing so you may only use 2 chains single wrapped. (one per frame rail) May not go through the body.
  7. No duct taping of leaf springs
  8. Max front and rear bumper height to the bottom is 22” and max low on the rear is 15” to the bottom.

(10). Windows:

  1. You may have no more than 2 window bars (2 bars front window, 2 bars rear window) in the front and rear window and each bar no more than 9” from window center.
  2. Bars may not be bigger than 36” long by 2” x 2”.
  3. Bars 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. Plate cannot be mounted on the trunk lid itself.
  4. If using rear window bars 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.
  5. No wiring or chaining of any window openings.
  6. Window bars may not be attached to the halo bar or any cage components.

(11). 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 in original stock location and position. Radiators may be mounted in such a way to hold the radiator in place, not strengthen the core support. For mounting radiators, you may use up to 4 – 3/8” all thread. This may pass thru the bottom and top of the core support. If you have no lower or upper mounting area, you may be attached two 2”x 6” 1/8” flat steel on the top and bottom and must be welded to the core support they must be outside the fan. Or if welding radiator in place you may use four 1” welds, one percorner. No added metal may be used to mount the radiator.
  3. No radiator guards allowed other than 1/8” expanded metal or old condensers may be used. They may only be wired in or a maximum of six 1” welds may be used to hold it in place.
  4. You may not add cooling capacity. No supplemental cooling devices allowed (electric fans are allowed).
  5. Radiator loops may be used.
  6. Front core support cannot be moved back from its factory location. It must stay bolted to the fenders the same way that it came from the factory.
  7. You may have up to 1” all-thread, it may go from the hood to the frame, see Body mounts #8.
  8. Radiator core support seam welding is NOT allowed. Only slight modifications due to bumper brackets for mounting core support back into the original position is allowed, Officials discretion.
  9. Radiator supports may not be welded to the frame, bumper brackets, bumpers or anything else.
  10. No FOAM fill can be used.


  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 used to be. Must be securely mounted behind the driver’s seat to the sheet metal with bolts, metal straps, or chain. No seat belts or pull tie straps may be used. Or you may suspend it on your cage, follow cage rules. No other source of gas/ether inside the car at all.
  4. 7-gallon (within reason) max tank maximum may be used must fit within gas tank protector specs.
  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 the engine compartment.
  6. Tranny and fuel coolers are allowed. These coolers cannot be placed to reinforce the car. No bolts may extend through the frame to create a body mount.
  7. If you are not using a gas tank/trans cooler protector, the fuel cell and tranny cooler must be 4” away from the rear sheet metal. So, either way protector or not nothing can be within 4” of any sheet metal.


  1. Electric fuel pumps are allowed. The on/off switch must be easily accessible and clearly marked with bright paint.


  1. Batteries must be secured inside the car 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.
  3. Rusted out holes in your floor sheet metal may be patched where components will be mounted or for driver’s safety with sheet metal only. You may not patch clean and solid floors.


1- No split rims or studded tires allowed.

2- You must start with a stock wheel, no bead locks or full wheel centers. You may add a piece of .” rolled or flat steel to the exterior rim lip only. Small wheels center’s no larger than 8” only and valve stem protector. No foam filled tires and no wheel weights.

3- All cars must be able to demonstrate the ability to stop at any time. If your brakes do not work, you will not compete.

4- You may not change tires after inspection without official’s consent.


1- You must have an air cleaner over the carburetor all at times during the event.

(16). CUT OUTS:

1- Clearance cut outs over the wheel openings are legal but can’t be re-bolted or welded.

2- (9) 3/8” bolts with 1.5” washers may be added to the hood to ONLY hold hood to the hood frame underneath.

3- If inspection holes and fire holes are determined to be too small you will be asked to cut them larger.

4- Remember 2-8” holes need to be in the trunk and a 20” hole (bolted hood) 30” hole (welded hood) in hood for inspection or you’ll be sent back around



  1. Ten plates not to exceed a 6” by 4” area by 3/16” 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” May not be welded to the body or any other bolted on frame components without permission.
  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 patch may 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 you must use factory type and strength parts.
  7. No frame wedge blocking.