IMCA Southern Limited Modifieds

Revisions/clarifications are hilighted in blue, recommendations are italicized.

1. SAFETY EQUIPMENT: Rules apply at all times car is on track. Snell-rated SA95 or SA2000 helmet required. Roll bar padding required in driver compartment (Fire retardant recommended). SFI-approved full fire suit, fire retardant neck brace, gloves and shoes required. Recommended: Fire retardent head sock and underwear; head and neck restraints; collapsible steering shaft. Driver-side window net required, minimum 16"x20" ribbon or mesh style, and must be mounted so quick release latch is at top front of window. Sprint car cage net is allowed, but must wear arm restraints. Minimum three-inch wide five point safety belt assembly required, must be mounted securely to roll cage, recommended to be no more than one year old. Kill switch required within easy reach of driver and emergency personnel, must be clearly marked ‘OFF’ and ‘ON’.
2. FRAME: OEM complete, 1978-1987, midsize GM metric full frame only. Minimum wheelbase 107-inches, maximum 109-inches, both sides. Frame must be full and complete, cannot be widened, narrowed, shortened, lengthened, or be cut, bent, or altered to change suspension brackets, except upper control arm brackets on front end. All frame bolt holes must remain in OEM location. Front frame horns may be removed in front of steering box. Front frame may be cut for radiator clearance. Frame may be notched for seat clearance. Transmission crossmember mounts may be removed, no further forward than frame welds. Rear of frame, behind upper shock mounts, may be replaced with round, square, or rectangular tubing. No part of frame can be lower than five inches from ground except front crossmember. No other frame alterations allowed!
3. ROLL CAGE: Must consist of continuous hoops, minimum 1.50-inch O.D. tubing, with a minimum wall thickness of.095-inch for main cage. Cages must be steel or chrome-moly. Main cage no further forward than rear of engine and no further back than front edge of rear tire. Four bars, two per side, may extend from main roll cage to main frame points in front of the upper control arms. These bars may have two additional  braces per side to the main frame. Six bars may extend from the main cage to the rear. X-bracing is allowed. 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. All bars forward of cage must be lower than hood.
4. DOOR BARS: Minimum three driver side door bars required, must be parallel to ground and perpendicular to driver, and welded to front and rear of roll cage. Minimum two passenger side door bars required, must have at least one cross door bar, horizontal or angled. Steel door plate, 18 gauge or .049-inch minimum thickness, must be securely welded to outside of driver side door bars and cover area to protect driver.
5. BODY: (See diagram for specific dimensions) Body must be same width, front to rear, and parallel to OEM frame. Aluminum or fiberglass hoods allowed, must completely cover top of radiator and engine, extending from nose to interior deck and enclosed at rear. Engine compartment must remain open (no side panels). Must have front and rear roof supports. No Gremlin roofs. No plastic body panels or filler panels allowed. Must have complete interior deck from side to side, must be aluminum or sheet metal. Quarter panels must remain 90-degrees to ground, maximum 45-degree bend 4-inches from bottom and 2-inches from top of doors and quarters.
6. DRIVER COMPARTMENT: Must have minimum three 5/16-inch O.D. windshield bars in front of driver. Aluminum cowl panel in front of driver can be no wider than cockpit. Full, high-back, aluminum racing seat required, must be securely bolted to roll cage and support system, not floor pan. Floor pan must be metal or aluminum and cover entire driver compartment. 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. No oil coolers allowed in driver compartment. No devices that would enable driver adjustment to alter wheelbase or for weight jacking while car is in competition. No mirrors.
7. FRONT SUSPENSION: All components must be steel, unaltered OEM, in OEM location, and match frame. No jack bolts allowed. Adjustable spring buckets are allowed. Must use OEM upper and lower A-frames and mounts.  Upper A-frame mounts may be modified and moved for caster and camber adjustment, but must remain OEM material. Lower A-frame mounts and bolt holes on frame must be in OEM location, mount may be notched for clearance. All A-frame bushings may be aftermarket, but no bearing type. OEM style ball joints only, may be tacked in. Sway bars(optional) and brackets must remain OEM.
8. STEERING: All components must be steel, unaltered OEM, in OEM location and match frame. No grinding, lightening or welding on any steering parts. Spindle may be reamed and bolt on spindle savers are allowed. Steel steering shafts and knuckles only. Steering quickener (optional), steering wheel and quick release (required) may be aluminum. Power steering pump and reservoir must remain one unit. Driver compartment steering may be modified, must be kept on left side. No rack and pinion.
9. SHOCKS: One steel shock per wheel only. Shock must be in OEM mounts and location, using OEM style shock. Mounting spacers and weld or screw-on shock ends allowed. No air or coil-over shocks, remote reservoir shocks or schrader valves.
10. SPRINGS: One steel spring (racing allowed) per wheel only. Minimum 4.5-inches O.D., non-progressive coils only. No torsion bars or air bags.
11. REAR SUSPENSION: All control arms and mounts must be steel, unaltered OEM, in OEM location, and match frame. No jack bolts allowed. Adjustable spring buckets allowed, may be dropped as long as they remain in OEM location. Lower spring cups may be placed on housing only. Control arms may be reinforced, but cannot be shortened or lengthened, must remain OEM length. All control arm bushings may be aftermarket, but no bearing type. No suspension parts may be altered or lightened. No aluminum parts allowed, other than bushings.
12. REAR END: Must use OEM 7.5-inch GM 10 bolt rear end (bracing optional), must remain stock width. No Ford or floater rear end allowed. Housing end, from control arm mount out, may be modified with 3-inch tubing to accept 9" Ford axle. If Ford axles are used, rearend must remain minimum GM width or maximum 3-inches wider. Steel components only. OEM mounts on lower control arms must remain in OEM location on original 7.5-inch tube housing. Aftermarket axles, mini-spools and C-clip eliminators allowed. Locked rear ends only, no torque dividing differentials allowed. No full or aluminum spools allowed. Pinion angle can not be changed. Any gear ratio allowed but housing must remain unaltered. No quick change devices.
13. BUMPERS/RUB RAILS: Steel only. Two bar front bumper and single bar rear bumper must be used on car at all times and welded, or bolted securely. Must be maximum 1.50-inch O.D. tubing, .095-inch wall thickness on front and 1.75-inch tubing, .095 wall thickness on rear. Maximum 1.50-inch O.D. tubing, .095-inch wall thickness fuel cell protection bar required, may be welded to rear bumper. See diagram for bumper heights. Rear bumper may be maximum 6-inches beyond rear deck. All bumpers and rub rails must be capped with no sharp edges. Single bar rub rail from front to rear wheel allowed on each side.  Maximum 1.50-inch O.D. tubing and .095inch wall thickness, must be mounted to cage at front and rear of rub rail. No center supports allowed.
14. TIRES/WHEELS: Must use Hoosier ‘500’ tire. No siping allowed. Grooving allowed. No re-caps. Must use 15”X 8” steel wheels. Any offset allowed. External steel bead lock allowed on right rear only and it cannot make wheel any narrower than 8-inches and no wider than 8.75-inches. One foam or plastic mud cap allowed on right rear only. Must use minimum 1-inch O.D. lug nuts and 0.625-inch studs are recommended. No wheel spacers allowed with OEM studs. Wheel adapters are treated as spacers and may be aluminum, maximum 1.50-inches thick. No bleeder valves.
15. BRAKES: Must be steel OEM, operative three wheel, drum or disc. Must maintain minimum OEM dimensions for hubs/rotors and calipers, cannot be lightened. Bolt pattern may be changed. 0.625-inch studs allowed. Single or dual aftermarket master cylinders allowed. Driver adjustable dual pedal brake bias allowed. Additional proportioning valve (in-line type) allowed, must be out of driver reach. Rear rotors may be aftermarket, minimum 0.810-inch thickness, maximum 12-inch O.D. Vented rotors only, no scalloped, single phase or drilled rotors allowed. Rear caliper brackets must be welded to housing.

16. EXHAUST: Must use Schoenfeld headers. GM: #161, #151 with 1.625-inch tubes and 3-inch collector. Chrysler: #461, #461W2, #462W2. Ford: #361, #362, #562, #562-4B #563-4B. No header modifications allowed. No exhaust sensors, cross overs, turn outs or balance tubes. See tracks for muffler rules.
17. FUEL SYSTEM: Maximum 22-gallon capacity, racing fuel cell required. Must be securely mounted, with minimum 2 steel straps around entire cell, between frame rails in trunk area only. Fuel cell vents, including cap vent, must have check valves. Fuel cell protection bar required, must cover rear and extend past both sides of cell. No part of cell can be lower than protective tubing. OEM mounted, mechanical push rod fuel pumps only. No regulators, bypass fuel systems, pressurized, or return lines allowed. CARBURETOR (one only): Holley(unaltered) #4412 or #0-80583-1, 500 cfm two barrel may be used on any engine. OEM GM Quadrajet or two barrel may be used on Chevy. OEM Motorcraft four or two barrel may be used on Ford. OEM Carter or AFB four or two barrel may be used on Chrysler. OEM carburetors must remain unaltered, circle track floats may be installed. No other carburetors allowed. Adapter/spacer allowed, maximum 1.250-inches thick, including gaskets. No driver compartment adjustable carburetors or spacers. Limit of one fuel filter. No cool cans. Any air cleaner allowed.
18. FUEL: Gasoline only. No performance enhancing additives or scented additives. Fuel must pass both dialectric meter and chemical tests. Fuel sample may be taken from any car at any time. Penalty for illegal fuel is disqualification from event and $250 fine - first offense.
19. WEIGHT: Minimum weight limit of 2,350 pounds after race with driver in car. Weights must not be used in driver compartment or outside body. All weights must be securely mounted with at least two, .5-inch bolts, painted white with car number on it. No titanium, magnesium, stainless steel or carbon fiber components. Solid steel fasteners only.
20. BATTERY/STARTER: One 12-volt battery only. Must be shielded and securely mounted. Aftermarket starter allowed, must bolt in OEM location. Must have capability of starting without being pushed or pulled. Must leave initial staging area on demand, unaided, or go to rear of that race.
21. GAUGES/ELECTRONICS: OEM style ignitions only. GM: HEI distributor(must remain one unit) or point distributor allowed. Ford/Chrysler: may use OEM ignition, including OEM boxes, or HEI distributor. Any module may be used that fits inside the distributor with no alteration. Vacuum advance may be removed and pick-up coil locked. No external coils allowed, unless using point distributor. No GM or aftermarket ignition boxes allowed. No electronic traction control devices ($10,000 fine).
22. TRANSMISSION/DRIVE SHAFT: Only OEM production transmissions allowed. No aftermarket transmissions allowed. No ‘in and out’ boxes or quick change devices allowed. With engine running and car in a still position, must be able to engage car in gear and move forward, then backward. Functioning shift levers must be in OEM location. Transmission fluid coolers allowed. Flywheel, flexplate and converter must be steel.
Automatic: Any OEM automatic transmission allowed. Must use functioning, minimum 10-inch diameter steel torque converter. No direct drives, couplers, valved pumps, or bleeder style valve bodies. Must have at least one forward gear and reverse gear, gears must function. Must have an approved scattershield constructed of .125-inch by three-inch steel, 270 degrees around top of flexplate. GM automatic must be used with GM engine, may be used with Ford or Chrysler engine. Stall converters allowed. Steel OEM style flexplate only, must be bolted directly to end of crankshaft.
Manual: 3, 4 or 5 speed OEM manual transmissions only. All gears must function. Must have functioning 10.5-inch minimum diameter clutch and pressure plate bolted directly to steel flywheel. These components must rotate, consistant with engine rpm, while car is in any gear. Must use explosion-proof steel bellhousing 180 degrees around top of clutch and flywheel. No mini-clutches or couplers. Minimum 9-inch diameter Ford clutch allowed. Hydraulic slave cylinder/throw out bearing allowed.
Drive Shaft: Minimum 2-inch diameter, white, steel drive shaft only. Steel slip-yokes only. 360-degree drive shaft loop required, constructed of at least 0.125-inch by 2-inch steel, or 1-inch tubing, mounted 6-inches back from front U-joint.
23. ENGINE COMPARTMENT: Rear of engine (bellhousing flange) must be mounted at least 70-inches forward from centerline of rear axle. Minimum 11-inch engine height from ground to center of crankshaft. One radiator allowed, steel or aluminum, 27-inches by 19-inches maximum in size, must be mounted in front of engine. Racing cap and electric fans allowed. No sprinklers. Catch can required. Power steering pump and reservoir must remain one unit and mount in front of engine. Side engine mounts (OEM or 45-degree style) must be steel, aluminum mid-plate allowed.
24. ENGINE SPECIFICATIONS: Must use OEM cast iron, American make V-8 small block engines only. All engines must be able to be used in conventional passenger car without alterations. External engine casting and threaded holes cannot be altered. No aluminum, titanium or carbon fiber components allowed. BLOCK: GM (chevy only): 283, 302, 305, 307, 327, 350. Ford: 260, 289, 302, 351. Chrysler: 273, 318, 340, 360, no hemis. Maximum cubic inch limits: GM 364 c.i., Ford 360 c.i., Chrysler 370 c.i., no tolerance. No 400 or larger cubic inch parts allowed. Flat top or dished cast pistons only, Chevy must use 4 valve relief. No gas ported or floating pistons. 3.48-inch maximum GM stroke. Maximum 175 lbs. per cylinder compression, no tolerance. Engines may be balanced and block decked. Oil filter system must remain OEM. ‘Wet’ oiling system only. Racing oil pans allowed. No accusumps. OEM rods. Chevy must use maimum 5.7-inch rod. Steel or cast OEM crankshafts only. No splayed main caps. Engine bolts may be after market. Fluid dampener balancer allowed. No roller bearings allowed. INTAKE: Must use unaltered OEM cast iron two or four barrel intake. No aftermarket, hi-rise, marine or bowtie intake manifolds. No porting, polishing or alterations of any kind. Ford may use aluminum intake, no under air or hi-rise. Intake must have vacuum fitting. Belt driven, OEM style water pumps only, no aluminum water pumps on Chevy engine. CAMSHAFT: Non-roller hydraulic cam/lifters only. Maximum 0.450-inch lift, measured at the valve. Must pull 12-inches of vacuum at 1200 rpms. No alterations of any kind may be made at time of tech. Track equipment being used for tech is final. Lifter bores cannot be altered. Must be chain driven, no gear/belt drives. CYLINDER HEADS: Must use one of the following OEM GM cylinder heads: 126, 185, 336, 441, 445, 487, 493, 598, 624, 862, 882, 920, 993, 997 (last 3 digits), with valve no larger than 1.94-inch intake and 1.50-inch exhaust. No X-heads. Any cast iron OEM Ford and Chrysler heads allowed with valves no larger than 2.04-inch intake and 1.70-inch exhaust, head numbers will be listed in 2006. Headers must bolt directly to heads with correct numbers. No vortec, bowtie, SVO, W-2 or aftermarket heads allowed. No porting, polishing, or alterations to heads of any kind. Flat milling allowed. Guide plates, screw-in studs (0.375-inch max) and polylocks allowed, no stud girdles. Stamped steel, OEM style, stud mounted (0.375-inch max) rocker arms only. Chrysler may use OEM rocker arm bars. Any length push rods allowed. OEM diameter springs must match heads.
25. ENGINE CLAIMING RULES:
(A) $500 cash and exchange claim on engine, $50 goes to wrecker for pulling engines.
(B) Claim does not include - 1. flywheel, 2. clutch, 3. pressure plate, 4. bellhousing, 5. breathers, 6. carburetor, 7. starter, 8. motor mounts, 9. oil/temp. sending units, 10. fan and pulleys, 11. clutch ball, 12. clutch arm, 13. throw out bearing, 14. dip stick, 15. water pump, 16. fuel pump, rod and plate, 17. distributor, 18. plug wires, 19. water outlet and restrictor, 20. headers.
NOTE: During engine claim, inspect heads and intake, and one spark plug must be removed to check pistons prior to transfer of engines. If, at this time, an engine is found illegal, driver is disqualified and suspended from all I.M.C.A. sanctioned events until such time as a $250 fine is paid, for first offense. Exchange of engines may proceed depending on cirumstances. Decision to proceed is at descretion of track officials and/or I.M.C.A.
26. ENGINE PROTEST PROCEDURES: Within 5 minutes after race, any driver starting feature may, for $250, protest any engine. $50 of the protest fee goes to track and will not be refunded, regardless of protest outcome. Driver may not protest another driver finishing in a position behind them and may not protest same driver more than once per calendar year. Under this protest, following MUST be inspected: intake manifold, cylinder head (removal required), stroke, and visual inspection of crankshaft (pan may be removed). $200 will be returned to protestor if engine is found illegal. If engine being protested is found legal, $200 protest fee will be paid to driver being protested. If parts are found illegal, or if driver refuses to submit to protest, first infraction will result in forfeiture of all cash and contingencies, trophies and points earned in feature.
27. POINT STRUCTURE /PROCEDURES:
28. EIRI: (Except in rare instances) Decisions of officials are final and binding without exception. In some cases, track safety rules may take precedence over I.M.C.A. rules - any discrepancy between I.M.C.A. and track rules should be brought to the attention of I.M.C.A. Any rule changes or clarifications during the course of the year will be published in Inside I.M.C.A., the official newsletter of I.M.C.A., and will be considered as an official part of these rules.

ARTICLE XV - ENGINE CLAIM PROCEDURES:
NOTE: I.M.C.A. reserves the right to refuse issuance of an I.M.C.A. claim card, and further reserves the right to revoke a driver's claim card and claiming privileges if and when deemed necessary.
Dollar amounts for engine claims are as follows: Hobby Stocks - $325; SportMods™ - $425; Stock Cars - $425; Modifieds - $525; Sprint Cars - $825 (or spec engine head claim - $800) . Items not included with claim can be found in each division's rules.
1. Any driver that finished in top 20 in point standings at that track the previous year is eligible to claim on opening night. Driver must have been at track on opening night to claim second night of season. Following that, no driver may claim unless he/she has competed at that track the two previous consecutive sanctioned track point events. No driver may claim same driver's engine more than once during current calendar year. Drivers changing cars, or provisional starters, cannot claim.
2. First four position finishers must report directly to claim area and are subject to engine claim by any other driver finishing fifth on back in feature that has not been lapped by the fourth place driver. Failure to report directly to claim area will result in disqualification and loss of money and points for first infraction (engine is still claimable); will be treated as engine claim refusal for second infraction. (Exception: If car is involved in an accident or is in any other way rendered unable to report directly to claim area immediately following feature finish.)
3. Driver making claim must drive his race car immediately after finish of feature, under its own power, directly to claiming area. Highly recommended that only involved drivers and officials be allowed in claiming area, and that all drivers remain in their cars. There is to be no communication of any kind between drivers and anyone outside the claim area.
4. Claims must be made to official immediately after end of feature race, and correct amount of cash, valid I.M.C.A. License and claim card must accompany intention to claim. Driver may not claim until he/she has received license and claim card from I.M.C.A. Replacement claim card may be purchased for $9.95.
5. Only driver may claim engine and only driver may agree to sell or refuse to sell engine. In case of multiple claim on same engine, a drawing will be held to determine which driver gets the engine. The claim is not charged to those drivers not awarded the claim. Should the first eligible driver withdraw his claim, the next qualified driver will be allowed the engine claim. Should any driver voluntarily withdraw a legal engine claim, he/she will be charged with a claim and it will result in a $200 fine.
6. Driver allowed one claim ONLY per event, regardless of outcome of that claim. For example, driver claiming engine cannot claim shocks or carburetor. However, driver being claimed is subject to all items being claimed by different drivers in same event.
7. Promoter may claim the engine of any driver finishing in the top ten (or any driver in the feature event, with permission from I.M.C.A.) immediately following feature, unless that driver has made a legal claim in that event. Any promoter driving, owning, sponsoring or affiliated in any way with an I.M.C.A. car in competition forfeits his/her right of promoter claim. Driver claim takes precedence over promoter claim.
8. Once an engine claim has been made and accepted, the car is to be pushed where removal will take place and the engine is not to be started, under any circumstances. Any driver starting a claimed engine is disqualified from that event and will be suspended from all I.M.C.A. sanctioned events until such time as a $100 fine is paid to I.M.C.A. All claimed engines must be removed from car at the track. Claimed engine must be completely removed within a reasonable amount of time, at the discretion of track officials.
9. Refusal to sell forfeits all cash and contingency winnings for feature, any trophies earned, plus ALL I.M.C.A. points in all claim divisions for the season. Any driver refusing to sell engine, when claimed within rules, regardless of his reinstatement with I.M.C.A., loses his right to claim any I.M.C.A. driver's engine for 12 calendar months from date of reinstatement. Claim is not charged to claiming driver in case of a refusal.
10. First refusal will result in loss of ALL I.M.C.A. points in all claim divisions for the season and will also result in driver being suspended for 30 calendar days from I.M.C.A. events in all claim divisions from date of refusal and until cash fine ($1,000 - hobby stocks and SportMods™; $1,500 - stock cars; $2,000 - modified and sprint) is paid to I.M.C.A. Fine must be in the form of a cashier's check or money order and be received in the I.M.C.A. office prior to driver returning to competition. Some tracks may also suspend car for duration of penalty. Second refusal will result in driver being suspended from I.M.C.A. events for one year from date of refusal and until $5,000 cash fine is paid to I.M.C.A. Third refusal results in permanent suspension from all I.M.C.A. sanctioned events.
11. Cylinder block may not be altered in such a way as to prevent it from being used in a stock application. Stock approved OEM components must be able to be used in their stock location. Any sabotage discovered to claimed engine will result in same penalties as engine claim refusal in that respective division. Drivers are to be held accountable for any sabotage discovered while pulling engine, and will be responsible for any and all penalties as a result of any sabotage. Claim will be disallowed and money returned to claimer.
12. After a driver has claimed two times, the next two drivers he/she claims have option of engine exchange or cash amount. In event of an engine exchange, claiming driver pays a total of $50 for both engines to be removed. After a driver has been claimed two times, they are eligible to claim as many engines as they have had claimed. (Examples: Once a driver has been claimed three times, that driver will be eligible to claim three engines for cash amount, and the next two would be exchange option by claimed driver. Once a driver has been claimed four times, he/she will be able to claim four engines for cash amount, and next two would be exchange option by claimed driver).
13. A disqualification of claimer or claimee will not affect a legal claim. The engine will be pulled and transferred prior to any penalties being assessed.
14. Unsportsmanlike conduct during claim procedure, or while pulling engine, will result in an immediate minimum $100 fine and/or suspension.

ARTICLE XVI - SHOCK CLAIM PROCEDURES: No driver may claim same driver's shocks more than once during current calendar year. Driver claiming shocks cannot claim engine or carburetor on same night.
1. Follow all engine claim procedures and eligibility requirements. Penalty for shock claim refusal is $1,000 and 30-day suspension.
2. I.M.C.A. Modifieds, Stock Cars and SportMods™ - Any driver finishing fifth on back in feature that has not been lapped by the fourth place driver can claim any shock for $50 from any of the top four drivers. One or all shocks may be claimed, counting as one claim.
3. I.M.C.A. Hobby Stocks - Any driver finishing fifth on back in feature that has not been lapped by the fourth place driver can claim any shock for $20 from any of the top four drivers. One or all shocks may be claimed, counting as one claim.
4. Should any driver voluntarily withdraw a legal shock claim, he/she will be charged with a claim with no penalty.

ARTICLE XVII - CARBURETOR CLAIM PROCEDURES: No driver may claim same driver's carburetor more than once during current calendar year. Driver claiming carburetor cannot claim engine or shocks on same night.
1. Follow all engine claim procedures and eligibility requirements. Penalty for carburetor claim refusal is $1,000 and 30-day suspension.
2. I.M.C.A. Stock Cars and SportMods™ - Any driver finishing fifth on back in feature that has not been lapped by the fourth place driver can exchange carburetor with any of the top four drivers. Both carburetors must be inspected and deemed legal prior to exchange. Should either carburetor be illegal, claim is void and driver is disqualified.
3. I.M.C.A. Hobby Stocks - Any driver finishing fifth on back in feature that has not been lapped by the fourth place driver can claim carburetor of any of top four drivers for $50. Claimed carburetor must be inspected prior to removal. If found illegal, claim is void and claimed driver is disqualified.
4. Should any driver voluntarily withdraw a legal carburetor claim, he/she will be charged with a claim with no penalty.