2014 Limited Modified Rules


1. Engine.
GM: 360 cubic inch maximum. Must be 350 block & stock 3.48 crank. No 400 blocks.

Ford: 361 cubic inch maximum. Stroke must match block. Example: 351W stock block & and 3.50" stroke

Mopar: 370 cubic inch maximum. Stroke must match block. Example 360 stock block & stroke.

2. After market crankshafts and any steel connecting rods allowed.

3. Lift rule: .480” at the valve. May be checked at any time. Stud mounted Roller rockers allowed. Must pull 16# minimum of vacuum at 1200 RPM.

4. No roller cam shafts or lifters. No bleed down lifters.

5. No titanium valves.

6. Heads: Stock OEM cast iron, World Products SR, Vortec, or #EQ-CH350I for chevy or #EQ-CH318B for chrysler. 2.02” € intake & 1.60” exhaust valves max,  no Bowtie or SVO heads.

7. no angle plugs allowed. No porting or polishing of heads & intake. No match porting of intake to heads. No aluminum heads.

8. No mismatching of engine parts GM to GM, Ford to Ford.

9. No aluminum parts except for intake manifold, pulleys, valve covers, radiators, & water pumps.

10. Transmission: Manual must be OEM 3 or 4 speed only. Must have all working gears. Steel or aluminum flywheel with minimum 10" clutch disc. Automatic must use minimum 10" working torque convertor. No direct drives or mini clutches. No internal clutch transmissions.

11. Cars running this engine/transmission configuration must weigh minimum 2450#. Maximum spoiler 8" including all angles and wicker bill.

1. 602 GM crate engine. Original GM sealing bolts or approved rebuilder only. Only modifications are what is allowable through GM certified rebuilder.

2. Same clutch and transmission rules as Option #1

3. Cars running crate engine option must weigh minimum 2400# at all times with driver. Maximum spoiler 8" including all angles and wicker bill.

1. Any American made engine allowed. Steel heads block & oil pan only. All engines must be able to be used in conventional passenger car without alterations. Engine mounts cannot be removed or altered. Castings and fittings must not be changed.

2. No Roller cams or lifters. Any stud mounted rocker arms ok, no shaft rockers except on Chrysler.

3. Transmission: Manual must be a production 3 or 4 speed and have at least two forward gears & one reverse, plus a neutral position. Transmission must be one of the following designs:
MANUAL: Must have a standard OEM cast & working disc-type clutch or approved cone or disc type coupler inside an explosion proof steel bell housing. One fly wheel only. Diameter of clutch disc must be a minimum of 5.5 inches. Clutch assembly must be steel, except housing, which must be steel and/or aluminum. Bell housing can have only a hole for throw out bearing lever or hose, must be 270 degrees around top of clutch and flywheel area. Standard or reverse mount starter allowed, must directly engage flywheel. No internal clutch type transmissions, except automatics.
AUTOMATIC: Must remain in OEM or OEM replacement case with a functioning OEM appearing pump. Must have an approved scatter shield. Scatter shield must be constructed of minimum of .125-inch by three-inch steel, 270 degrees around flex plate. Converterless powerglide ok.
Cars running this engine/transmission option must weigh minimum 2650#. Maximum 5" spoiler.

The following rules apply to all cars:
Any car running a 3 link type suspension, with mounts welded solid to rearend and no floating birdcages will get a 50# weight break. Springs may not be mounted on trailing arms.

1. With engine running and car in still position, must be able to engage car in gear & move forward, then backward..No five speed (or more) transmissions, in & out boxes, or quick change devices allowed. Functioning shift levers, must be in OEM location on all OEM production type transmissions. Flex plates must be full steel, unaltered OEM or OEM replacement. Flywheel/flex plate must bolt to engine between clutch assembly & crankshaft & all driving components within bell housing must rotate while car is in any gear.

2. Wet oiling system only. No external oil pumps. No rear drive pumps of any kind. No belt drive or electric fuel pumps.

3. BATTERY/STARTER: One 12 volt battery only, must be securely mounted between frame rails, and positive terminal must be covered. Car must have capability of starting without being pushed or pulled

4. FUEL SYSTEM: Alcohol or racing fuel OK. No additives. Oxygenated fuel ok. No aerosol carbs allowed. Carburetor can be no larger than Holley #4412 500 CFM 2 barrel and must pass inspection from top side with gauge. Choke horn may be removed. Must be stock ventura 1-3/8” May run stock rochester 2 barrel (subject to be pulled off and checked). Mechanical fuel pump only and must be mounted at front of engine. Racing fuel cell required, maximum 32 gallon capacity, must be in minimum 20 gauge steel container. Cell must be securely mounted behind rear axle, between rear tires, minimum of four inches ahead of bumper, minimum of ten inches above ground. Must mount with minimum two solid steel straps around entire cell, two inches wide and 0.125 inch thick. All cell mounts must be steel, securely welded to frame/cage. Protective tubing must cover rear and extend past both sides of cell. No part of cell shall be lower than protective tubing. Fuel cell vents, including cap vent, must have check valves. If fuel cell does not have aircraft style positive seal filler neck/cap system - a flapper, spring or ball type filler rollover valve is required. Pick-up must be on top or right side of cell. Limit of one fuel filter. No cool cans. Recommended: if a new car is being built or the fuel cell is being replaced, replace with 22 gal. Max cap

5. IGNITION: MSD 6AL or equivalent ignition allowed. Any HEI allowed. No magnetos. No unapproved cameras, transmitting or listening devices, timing retard controls, or digital gauges (including tach). No electronic monitoring computer devices capable of storing or transmitting information except analog tach. No adjustable ignition control boxes. One 12 volt ignition box allowed, must be out of driver’s reach. No additional ignition accessories allowed. Only change allowed to ignition box is one high-end rev-limiter setting. This setting can be changed through one chip only, or an internal setting inside box.

6. EXHAUST: Round tube headers only. All primary header tubes must enter directly into one collector at same point at end of header. No merge collectors or tri-Y. No exhaust sensors. Header mounted mufflers highly recommended.

7. TIRES AND WHEELS: Hoosier asphalt take-offs, Hoosier G60's, American Racer KK704, Hoosier E-mod A or H only. Grooving, grinding and siping allowed. Steel wheel only. 10” € maximum with take offs. 8" wheels with modified tires. Bead locks allowed. Plastic, aluminum or foam mud plugs allowed.

8. FRAME: 1964 or newer OEM perimeter American rear-wheel drive passenger car frame only. No sports car frames. Frame must be full and complete, cannot be widened or narrowed, and must be able to support roll cage on both sides, exceptions are: weight jack in original center line of spring tower allowed; frame may be cut a maximum 36 inches forward from center of rear end housing; horns may be removed in front of steering box and notched maximum one inch at bottom for tie rod clearance; front crossmember may be notched and boxed for radiator and/or steering clearance; maximum seven inch wide opening in side of spring tower for spring removal. Maximum two inch wide by four inch tall frame stiffener may be welded directly to outside of left side frame rail. NO right side raised frame rails. Minimum wheelbase 108 inches, maximum 112 inches, both sides. Maximum overall width shall not exceed 78 inches from outside of tire to outside of tire. No part of frame can be lower than four inches from ground except front cross member. 

9. ROLL CAGE: Must consist of continuous hoops, minimum 1.75 inch O.D. tubing, with minimum wall thickness of 0.095 inch for main cage, frame-mounted in at least six places, low carbon or mild steel recommended. Must consist of a configuration of front, rear and top hoops connected by tubing on sides or side hoops. Driver’s head must not protrude outside cage with helmet on. Roll cage must be securely supported and braced with minimum one cross bar in top halo. Foot protection bar required. Main cage no further forward than rear of engine. All bars forward of cage must be lower than hood.

10. DOOR BARS: All driver side door bars and uprights must be minimum 1.5 inch O.D. with 0.083 inch wall thickness. Minimum three driver side door bars, parallel to ground and perpendicular to driver, and welded to front and rear of roll cage. Passenger side must have at least one cross door bar, horizontal or angled, minimum 1.25 inch O.D. with 0.083 inch wall thickness, and one top door bar, minimum 1.5 inch O.D. with 0.083 inch wall thickness. Steel door plate, 18 gauge or 0.049 inch minimum thickness, securely welded to outside of driver side door bars and cover area from top door bar to bottom door bar and from rear hoop down-post to five inches in front of seat HIGHLY RECOMMENDED.

11. BODY: No composite body panels allowed except roof rock guard, hood scoop and front nose piece. Aftermarket plastic nose will be allowed, however bumper must be exposed on outside of nose. Body must be same width, front to rear, and parallel to OEM frame. Nose panel must be flat with no fins or scoops allowed. Cooling holes allowed. Nose panel may be no wider, or lower than two inches outside of front frame horns. Nose panel must remain within confines of front bumper. Engine compartment must remain open, no side panels FROM FAN TO MOTOR PLATE! Hood must be enclosed at rear. No panel in front of right door to engine compartment. No inner panels. No car covers. Must have front windshield and rear window support posts. Driver and passenger side windows must have at least 12 inch opening (height and width), measured at center of window, between lowest point at top of window, whether roof or roll cage, and highest point at bottom of window, whether interior or body. May use Lexan in sail panels. May use full windshield. Roof must be fiberglass or aluminum, full size and rounded down in all directions (see diagram). No dished roofs allowed. Driver roof hatch allowed. Maximum 1.5 inch rolled down rock guard allowed on roof front. No fins, lips, wings or spoilers on roof. Maximum four inch plastic skirting allowed on bottom of doors and quarters. No reflective doors or quarter panels. On right side, outside of tires must be widest part of car. On left side, body may be maximum one inch outside of rear tire for clearance.

12. DRIVER COMPARTMENT: Must have minimum three windshield bars in front of driver. Lexan or aluminum cowl panel in front of driver can be no wider than cockpit and no farther back than steering wheel. Minimum 0.125 inch aluminum, or 0.060 inch steel, complete floor pan required. Aluminum high-back seat only. Full containment type seat highly recommended. Must be bolted in, using minimum 0.375-inch bolts, next to left side frame rail and ahead of rear tires. Bottom of seat can be no lower than bottom of frame rail. Driver must be sealed off from track, driveline, engine, fuel cell, cannisters and pumps. Oil coolers must not protrude above interior. Accumulators cannot be mounted between driver and left-side door bars. No driver-adjustable devices allowed while car is in competition except brake adjuster. No mirrors of any kind. Drivers side window net recommended.

12. FRONT SUSPENSION: All components must be steel, unaltered OEM, in OEM location, and replaceable by OEM parts, exceptions are: tube-type upper A-frames with or without aluminum or steel cross shaft, and mounts can be moved; stamped steel OEM replacement lower A-frames or approved tube type lowers; rubber, nylon or steel lower A-frame bushings, no offset or bearing type; welded or bolted shock mount on lower A-frame; OEM or OEM replacement ball joints allowed. Lower A-frames must be right and left, and of same design. Lower A-frame mounts and bolt holes on frame must be within OEM specifications. Sway bar must be unaltered OEM. No bump stops.

13. STEERING: No rack and pinion. All components must be steel, unaltered OEM, in OEM location, exceptions are: outer tie rod end and adjustment sleeve may be replaced by a minimum 0.625 inch steel rod end and steel tube; spindles can be ground for brake caliper clearance only; unaltered, OEM replacement Pinto spindles; bolt on spindle savers allowed; steel steering shafts and knuckles only; driver compartment steering may be modified, must be kept on left side. Spindles must be right and left, and of same design. Quick release required - steering quickener and steering wheel may be aluminum. Idler arm, pitman arm, and center link must match frame.

14. SHOCKS: One steel, nonadjustable shock per wheel. One additional shock allowed in lift- or pull-bar area. No external or internal bumpers or stops. No threaded body, front coil-over, air, or remote reservoir shocks. No Schrader or bladder type valve allowed. Front half may be shielded. One or all shocks may be claimed per event for $100 each, following shock claim procedures.

15. SPRINGS: One steel, non-progressive coil spring per wheel only. Steel or composite leaf spring allowed. One additional steel or rubber spring allowed on pull bar or lift bar, may be progressive. Any coil spring must be at least 4.5 inches O.D. No torsion bars, air bags.

16. REAR SUSPENSION: No independent rear suspension. All components must be steel. No covers allowed. All trailing arms/link bars must be solid tubing. Rear of frame may be altered to accept leaf or coil springs. Steel coil-over eliminators, or steel or aluminum coil-over kits allowed - must conform to shock and spring rules. One mechanical traction bar (pull or lift, not both). Solid Pull Bar only! No spring bar, biscuit bar. No shock on the rear end! No brake floaters. Rubber bumpers allowed only on panhard bar and mechanical traction bar. No sway bar. Solid safety chains, cables or tethers permitted frame to axle housing only (cannot be mounted to any floating device), no springs or rubbers allowed.

17. REAR END: Any steel approved OEM passenger car or truck rear end (housing and carrier) allowed. Safety hubs (floater) allowed. All components must be steel, except lowering blocks, axle cap, drive flange. Inspection hole required in housing. Full steel spool, steel mini spool or welded rear ends only. Steel axles only. No quick change devices, or cambered rear ends. One piece drive flange only. No torque dividing differentials. No scalloped ring gears.

18. BUMPERS: Steel bumpers must be on front and rear at all times and welded or bolted. Rear bumper must be constructed of solid square, or minimum 1.25 inch O.D. tubing with 0.095 wall thickness, and no wider than five inches outside of rear frame rails. If wider than five inches outside rear frame rails, must be capped and bent forward 90 degrees, or constructed in a loop design. Must have at least one upright, minimum 1.25 inch with 0.065 wall thickness, from bumper to fuel cell guard. Two-bar front bumper must be minimum 1.25 inch O.D. tubing with minimum 0.065 wall thickness. mounted frame-end to frame-end, no wider than width of material outside frame horns and with bottom loop parallel to ground. Top bar must be directly above bottom bar, minimum 6.5 inches apart, measured center to center.

19. BRAKES: Must be steel approved OEM, operative four wheel, drum or disc. Must maintain minimum OEM dimensions for hubs/rotors and calipers, cannot be lightened. Bolt pattern may be changed. Larger studs allowed. Rear rotors may be after market 0.81 inch thickness (new). Vented rotors only, no scalloped or ceramic coated rotors. No pressure sensitive devices. One front to rear proportioning device allowed. Brake lines must be visible.

20. WEIGHT: No weights and/or loose objects in driver compartment, above interior deck or outside body. Weights must be securely mounted to frame or roll cage and painted white with car number on it. Must be attached with at least two 0.5 inch bolts. No titanium, magnesium or carbon fiber products. Only carbon fiber components allowed are rock guard and hood scoop. No gun-drilled, tubular, hollow bolts or studs. Steel fasteners only.