Mid-America Factory Stocks Rules 2024…Any rule clarifications or adjustments from previous are in red.
CAR/FRAME: American made rear-wheel drive, front-engine car or truck. No 4-wheel drives or convertibles. Minimum wheelbase 107 inches. Wheelbase must remain stock for the make and model of the car with a ½” tolerance. Frame must remain strictly stock with no alterations. You are allowed to replace rear frame rails from directly behind the shock mounts to the rear of the car. Motor must be in stock location. All frame/cage members must be welded solid. No heim ends and no adjustable members.
BODY: Stock appearing body, must have body lines. Fabricated steel or aluminum bodies ok but must be strictly stock appearing and in stock location. Slab style bodies will not be tolerated. Floorboard may be fabricated steel but must remain full front to rear and in strictly stock location. Firewall may be fabricated steel and can be no further back than oval hole(if there is no oval hole then the firewall can be no more than 8” from the back of the block to the front edge of the firewall). Aftermarket/fabricated firewall must be straight up and down(vertical). Aftermarket fiberglass roof allowed but MUST be stock replacement roof with stock appearing pillars (example performance bodies part #1015-81W). A 5” spoiler is allowed with a maximum 5” tall by 7” long sideboard. Spoiler must be at the rear of the deck lid. No enclosed cockpits/interiors. Stock appearing plastic nose and tail allowed but must match make of car/body. No fender flares allowed. The intent is for this to be a stock car class with as close to stock appearing bodies as possible. Stock bumpers or tube bumpers ok, must cut wrap around off the ends. No sharp edges. No bars connected to bumpers. No cow killer bumpers. All cars must have tow hook/chain on front and rear. Air filter guards/deflectors are limited to 12” in length measured from front to back.
ROLL CAGE: 6-point cage with at least 3 driver’s side door bars (and passenger side if passenger is present) and x-brace to rear of car. Must be welded to frame in a safe manner. Front and rear hoops are allowed. Min. tubing thickness is. .095. Unibody cars must be tied together at sub frames. 1.5” minimum tubing diameter for cage on existing cars, 1.75” minimum on any new cars and is highly recommended on all cars.
SUSPENSION: OEM suspension only. Stock mounts in stock location only. OEM type shocks with OEM style rubber ends only. No adjustable shocks allowed, NO heim end shocks! Racing springs allowed maximum of 15” rear spring. Maximum 1” rear spring spacer allowed. Front coil spring spacers allowed. NO weight jacks of any kind. No suspension stops. Aftermarket stock replacement upper steel A arms ok, right 8”-8 ½” long, left 8½”-9” long. No long stem or tall ball joints. NO adjustments on spring spacers(threaded type spacers must be welded).
Shock Claim: There will be a $100 claim and swap(the person claiming must give $100 and their shocks to the person getting claimed and in return will receive the claimee’s shocks). The driver who decides to claim shocks has to run on the lead lap, have raced the three previous class events at that racetrack and can only claim the winning driver. If driver doesn’t allow the claim, they will be DQ’d for the event along with a 7 day suspension at all Mid-America Factory Stock tracks and will not receive points or pay for that event. To claim shocks, the person claiming must proceed directly to the tech area and surrender their car/shocks immediately following the main event. The $100 must be submitted to a track official at the tech area within 5 minutes.
Shocks involved in claim must be traded in the same condition as they were raced in. Any intentional damage done to a shock prior to surrendering them in a swap will result in a $250 fine and a forfeiture of the swap.
REAR END: OEM original rear ends in stock location, or 9-inch Ford with stock drum or disc brakes, floaters ok, gears may be locked by welding of spiders. Mini spools or full spools can be used. No lightweight or aluminum components. All mounting points must match all mounting points on the rear end from original, no aluminum calipers. Rear lower spring seat must be welded to rear end housing tube, no bolt on spring seat mount. Rear trailing arm top mount cannot be more than 2 1/2” from center of bolt to top of rear end housing at any time. Rear trailing arm bottom mount cannot be more the 2 3/4” from bottom housing tube to center of bolt at any time. No rear control arm bushing with spherical bushing or off set bushing top or bottom front or rear of control arm. Cars with leaf springs must remain stock, no exceptions. Spring mounts on rear end need to be same side to side no off setting. No spring rubbers. Trailing arm mounts on rear end must be same height side to side. Trailing arms can be aftermarket but must remain stock length(Upper = 11 ¼”, Lower = 19 ¼”… +/- 1/8” max variance)
DRIVER’S AREA: Must have 5-poing safety harness no more than 2 years old. Aluminum seat only! Must have fire extinguisher, must have arm restraints or window net. Drivers head may be no further back than the “B” post/piller. No adjustments of any kind in cockpit area.
STEERING -steering must remain stock. Steering boxes must remain in stock location. Aftermarket steering wheel and quick release steering coupling are recommended. Quickeners or Quick steer boxes allowed.
RADIATORS -Any (1) radiator in original location. Water pump mounted fans only, No electric fans
TIRES/WHEELS: 8”, 9”, or 10” asphalt take offs allowed. 10” steel wheels max. Grooving and siping allowed. Bead-lock on right side only. All tires must durometer at least 45 at ANY TIME.
WEIGHT: 3,000 lbs after race with driver. Added weight ballast must be painted white and have car # on it. Must be mounted with 2 - ½” bolts min and be no higher than the door line.
BRAKES: Must be OEM front and rear. Right front shut off allowed. No proportioning valves. All brakes must work at all times. Dual master cylinders allowed. No adjusters allowed.
ENGINE: Must have V-8 engine, OEM size and configuration. 360 Max C.I.D. No stroker or destroke combinations allowed. No 400 blocks. Motors must be in stock location. May use solid motor mounts. 4 valve relief flat top with equal sized valve reliefs or dish pistons only. Piston/pin combo must weigh a minimum of 650 grams. No gas port pistons and No lightweight pistons or pins. Cast iron 76cc OEM heads only, may use EQ GM part number CH350I, Dart 10021070, Dart 10024360, World 4360, Ford World Products 53030. No vortec, angle plug and no double humps. 175lbs max compression measured at 5 rotations. No late model center bolts heads, no small chamber. OEM or Stock appearing replacement crankshafts only. No gun drilling or lightened counterweights. OEM connecting rods or stock appearing I beam maximum of 5.7 in long for GM (Ford and Mopar must be stock length as well). Cap screws ok. Hydraulic cam and flat tappet lifters only. Must maintain 14” of vacuum at 1200 rpm(Must have 3/8” pipe thread removable plug in intake vacuum port…Track will provide 3/8” pipe thread fitting with nipple to check vacuum). OEM heads may run 2.02” intake and 1.60” exhaust max valve size. EQ and Dart heads listed above may run 1.94” intake and 1.50” exhaust max valve size. Stock diameter valve springs only. 3/8 Screw in studs and guide plates ok. Stud mounted roller rockers ok. 1.5 ratio rocker arm. No stud girdles. Stock OEM unaltered aluminum or cast-iron intake only. No stock high performance or high rise. No bowties. May run Chevy- Edelbrock 2701/2101 or Weiand 7547 Ford- Edelbrock #7121 # 7181, #7183 Weiand #7515, #8023 or #7516. No porting or polishing of intake or heads of any kind. Aftermarket water pump, mini starter, pulleys, harmonic balancer and oil pans okay. Aftermarket power-steering pumps okay. All engines must have 1” inspection hole in oil pan as to be able to see rotating assembly with scope.
Unaltered sealed 602 crate engine is allowed. Must maintain 16” of vacuum at 1000 rpm(Must have 3/8” pipe thread removable plug in intake vacuum port…Track will provide 3/8” pipe thread fitting with nipple to check vacuum)
In reference to engines, ALL CARS must be labeled either “Crate”, “Vacuum”, or “Open” on driver side A-Pillar/Post.
RPM limit and chip will remain the individual tracks discretion and are listed below:
Red Dirt Raceway and Creek County Speedway
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Option 1 - No RPM Limit but must meet all above listed engine rules including vacuum rule
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Option 2 – 6,200 RPM Limit if all above listed engine rules are met with exception to vacuum rule
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Option 3 – 6,200 RPM Limit with 602 Crate option…Crate engine must remain sealed.
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NOTE: If you utilize option 2 or 3 then you must use MSD #8728 or MSD #8727CT for rev limiting. Rev-control units must be unaltered and mounted under the hood on engine firewall and accessible for inspection with rev limiter facing upward.
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Red Dirt Raceway requires any car utilizing fender exit headers to run a muffler of some type.
Enid
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Option 1 - No RPM Limit but must meet all above listed engine rules including vacuum rule
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Option 2 – 6,500 RPM Limit if all above listed engine rules are met with exception to vacuum rule
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Option 3 – 6,200 RPM Limit with 602 Crate option…Crate engine must remain sealed.
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NOTE: If you utilize option 2 or 3 then you must use MSD #8728 or MSD #8727CT for rev limiting. Rev-control units must be unaltered and mounted under the hood on engine firewall and accessible for inspection with rev limiter facing upward.
Salina
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Option 1 - 6,500 Limit and must meet all above listed engine rules including vacuum rule
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Option 2 – 6,200 RPM Limit if all above listed engine rules are met with exception to vacuum rule
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Option 3 – 6,200 RPM Limit with 602 Crate option…Crate engine must remain sealed.
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NOTE: If you utilize option 2 or 3 then you must use MSD #8728 or MSD #8727CT for rev limiting. Rev-control units must be unaltered and mounted under the hood on engine firewall and accessible for inspection with rev limiter facing upward.
Caney
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Option 1 - No RPM Limit but must meet all above listed engine rules including vacuum rule
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Option 2 – 6,500 RPM Limit if all above listed engine rules are met with exception to vacuum rule
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Option 3 – 6,200 RPM Limit with 602 Crate option…Crate engine must remain sealed.
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NOTE: If you utilize option 2 or 3 then you must use MSD #8728 or MSD #8727CT for rev limiting. Rev-control units must be unaltered and mounted under the hood on engine firewall and accessible for inspection with rev limiter facing upward.
Humboldt
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Option 1 - No RPM Limit but must meet all above listed engine rules including vacuum rule
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Option 2 – 6,500 RPM Limit if all above listed engine rules are met with exception to vacuum rule
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Option 3 – 6,200 RPM Limit with 602 Crate option…Crate engine must remain sealed.
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NOTE: If you utilize option 2 or 3 then you must use MSD #8728 or MSD #8727CT for rev limiting. Rev-control units must be unaltered and mounted under the hood on engine firewall and accessible for inspection with rev limiter facing upward.
Tulsa Speedway
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Option 1 - No RPM Limit but must meet all above listed engine rules including vacuum rule
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Option 2 – 6,500 RPM Limit if all above listed engine rules are met with exception to vacuum rule
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Option 3 – 6,200 RPM Limit with 602 Crate option…Crate engine must remain sealed.
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NOTE: If you utilize option 2 or 3 then you must use MSD #8728 or MSD #8727CT for rev limiting. Rev-control units must be unaltered and mounted under the hood on engine firewall and accessible for inspection with rev limiter facing upward.
Longdale
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Option 1 - No RPM Limit but must meet all above listed engine rules including vacuum rule
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Option 2 – 6,500 RPM Limit if all above listed engine rules are met with exception to vacuum rule
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Option 3 – 6,200 RPM Limit with 602 Crate option…Crate engine must remain sealed.
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NOTE: If you utilize option 2 or 3 then you must use MSD #8728 or MSD #8727CT for rev limiting. Rev-control units must be unaltered and mounted under the hood on engine firewall and accessible for inspection with rev limiter facing upward.
Ada?
FUEL/CARB: Pump Gas or Racing Gas, no Methanol or E85. Unaltered 4412 2bbl must pass gauge top and bottom. No thinned shafts. Aftermarket metering block ok. No XP or HP carbs allowed. Carb adapter/spacer cannot exceed 1” in total height.
IGNITION -One 12-volt battery only must be mounted securely in rear of driver’s compartment or trunk area. One stock type HEI distributor, module and coil in stock location only. No circuit boards in ignition system. Ignitions on/off switch must be clearly marked. No traction control devices of any kind. No digital gauges or tachs.
EXHAUST: Headers ok but must be mild steel with four equal size tubes going into one collector on each side. No step headers. Mufflers may be required at some racetracks.
TRANSMISSION: Any stock type automatic or manual. Automatics must have stock working 10” torque converter(no dummy converters) cannot be smaller with ring around it. No direct drives. Transmission Cooler ok. Manual must have single disc 10.5” clutch with flywheel and pressure plate that must be steel. All gears must work in a manual transmission. No mini clutches. Steel drive shafts only must be painted white and have a loop 6” from front u-joint. Clutch, flywheel, and pressure plate must way a minimum of 30 lbs and maximum of 50 lbs all together.
Our goal is to keep this class affordable and at the same time help the class grow by uniting the area race tracks into the same rule package.
Protest procedures will be at each tracks discretion and will follow each tracks individual protest policy.
Contact your local track with questions…
Rule clarifications can be directed to Mark Brill at 405-642-1157 OR Cody Brewer at 405-823-8095