ARK-LA-TEX SPEEDWAY
318 - 375 - 3470
LIMITED MODIFIED RULES - 2008
Schoenfeld mufflers, unaltered, stamped IMCA609, must be used.
1. FRAME:
1978-1987 OEM
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. Rear of frame, behind upper shock
mounts, may be replaced with round, square, or rectangular tubing. No other
frame alterations allowed.
2. ROLL CAGE:
Minimum
1.5 inch O.D. tubing, with a minimum wall thickness of.095 inch for main cage.
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.
3. DOOR BARS: Minimum
three driver side door bars required, minimum 1.5 inch O.D. and .083 inch wall
thickness, 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
4. BODY: (See
diagram) Must be same width, front to rear, and parallel to OEM frame. Engine
compartment must remain open (no side panels). Aluminum or fiberglass hoods
allowed, must completely cover top of radiator and engine, extending from nose
to interior deck and enclosed at rear. Must have front and rear roof supports.
Aluminum or fiberglass roof allowed, must meet body diagram. 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. Rear spoiler may be maximum 8 inches
in material height and maximum 67 inches wide. Spoiler may have stiffener, must
be 1 inch or more down from top. Maximum 3 spoiler braces allowed, must be
mounted in line. Spoiler braces must resemble all aspects of drawing. No fins,
lips or wings allowed.
5. 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. Aluminum
high-back seat only, must be securely bolted, using minimum 0.375-inch bolts, to
roll cage and support system. 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 of any kind.
6. 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. OEM upper A-frame may be replaced using
aftermarket upper A-frame (STEEL only), must display “IMCA approved” decal.
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/heim type. OEM style ball joints only, may be
tacked in. Sway bars(optional) and brackets must remain OEM.
7. 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.
8. 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, Schrader valves or bladder type
valve allowed.
9. 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.
10. 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. If upper spring cup uses all
thread, it must be securely welded to chassis. Lower spring cups must be
centered on housing. 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/heim type. Bushings cannot be drilled. No suspension parts
may be altered or lightened. No aluminum parts allowed, other than bushings.
11. 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.
12. 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 using minimum 0.375
inch bolts. 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, must cover
rear and extend past both sides of cell, 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, no center supports
allowed, maximum 1.50-inch O.D. tubing and .095-inch wall thickness, must be
mounted to cage at front and rear of rub rail.
13. TIRES/WHEELS:
Must use Hoosier ‘500’ Race tire. 27 by 8 by 15 or 26.5 by 8 by 15 ‘stagger
tire’ allowed. No siping allowed. Grooving allowed. No re-caps. Any offset
allowed. May use bead lock, on right rear only. External steel bead lock
only and it cannot make wheel any narrower than 8-inches and no wider than
8.75-inches. Steel bolts only. Outer foam or plastic mud cover allowed on right
rear only. Inner mud cover allowed on left rear only. No bleeder
valves.Must use minimum 1-inch O.D. steel 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.
14. 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. Rear rotors may be aftermarket,
minimum 0.810-inch thickness, maximum 12-inch O.D. Vented rotors only, no
scalloped, ceramic coated, single phase or drilled rotors allowed.
15. EXHAUST:
Must use
Schoenfeld headers. GM: #161, #151, #151E with 1.625-inch tubes and 3-inch
collector. Chrysler: #461, #461W2, #462W2. Ford: #351, #361, #362, #562, #562-4B
#563-4B. No header modifications allowed. Coated headers allowed. No
exhaust sensors, merge collectors, cross overs, turn outs or balance
tubes. Schoenfeld mufflers, unaltered, stamped IMCA609, must be used.
16. FUEL SYSTEM:
Racing fuel cell required, maximum 22 gallon capacity, must be in minimum 20
gauge steel container. Must mount with minimum two solid steel straps around
entire cell, two inches wide and 0.125 inch thick, between frame rails in trunk
area only. 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. 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. No cold air boxes allowed.
17. FUEL: Gasoline
only. Racing fuel allowed. No performance enhancing additives or scented
additives.
18. 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.
19. 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.
20.
GAUGES/ELECTRONICS:
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. 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.
21. 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, consistent 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.
22. ENGINE COMPARTMENT:
Rear of engine (bellhousing flange) must be mounted at least 70-inches forward
from centerline of rear axle. One radiator allowed, steel or aluminum, must be
mounted in front of engine. 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.
23. ENGINE SPECIFICATIONS:
Must use OEM cast iron, American make V-8 small block engines only. No
bowtie, SVO or W-2 components allowed. 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. Compression checked with one spark plug
removed, turned five engine revolutions. Engines may be balanced and block
decked. Oil filter system must remain OEM. ‘Wet’ sump oiling system only. No
accusumps. OEM rods. Chevy must use maximum 5.7-inch rod. Steel or cast OEM
crankshafts only. No splayed main caps. Racing oil pans allowed. One inch
inspection hole recommended in pan - no obstructions to crank and rods. If
obstructions are present, must remove pan for inspection. Engine bolts may be
aftermarket. Fluid dampener balancer allowed. No roller bearings allowed.
INTAKE:
Unaltered, approved OEM cast iron low rise, two- or four-barrel; or unaltered
Weiand aluminum – Chevrolet #7547-1, Ford 302 #7515, 351 Windsor #8023, 351
Cleveland #7516, Chrysler #7545. No porting, polishing, or alterations of any
kind, including cooling lines or plenum alterations to ANY intake. No OEM
hi-rise, marine or bowtie intakes. Ford may use OEM aluminum intake, no under
air or hi-rise. All intakes must have unobstructed 0.250-inch vacuum fitting.
Belt driven, OEM style water pumps only, no aluminum water pumps on Chevy
engine.
CAMSHAFT:
Non-roller hydraulic cam/lifters only. Hydraulic lifters must remain UNALTERED
OEM. No maximum cam lift. Must pull 12-inches of vacuum at 1200 rpms. Vacuum to
be pulled at intake vacuum fitting, not carburetor. 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:
Only GM OEM approved head numbers are (last 3 digits): 126, 185, 336,
441, 445, 487, 493, 598, 624, 862, 882, 920, 993, 997, with valve no larger than
1.94-inch intake and 1.50-inch exhaust. May use Engine Quest (EQ) Stock
Replacement (SR) cylinder head, part number CH350I, head must remain as
produced, valve sizes can not be changed. No porting, polishing, or unapproved
alterations to ANY cylinder head. Any cast iron OEM Ford and Chrysler heads
allowed with valves no larger than 2.04-inch intake and 1.70-inch exhaust.
Headers must bolt directly to heads with correct numbers. No vortec, bowtie,
SVO, W-2 or aftermarket heads allowed. Flat milling allowed. Guide plates,
screw-in shouldered 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 (no beehive valve springs allowed).
24. ENGINE CLAIMING RULES: Any driver in the same race on the lead lap may claim one of the top three finishers immediately after the “A” feature in the tech area. (A) $500 cash and exchange claim on engine. (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. (C) If driver refuses to submit to claim it will result in forfeiture of all cash and points earned in feature. Driver will also have to pay a $500 fine to be eligible to race again during the remainder of the points season. All proceeds from refusals will go towards the drivers point fund. (D) Driver may not claim another driver finishing in a position behind them and may not claim the same driver more than once per calendar year.
25. Protest Procedure: Any driver in the same race on the lead lap may protest another car immediately after the “A” feature in the tech area. $ 250.00 cash per component. $ 50.00 to the track, if legal, protested car gets $ 200.00 if illegal protester gets $ 200.00 back. If parts are found illegal, or if driver refuses to submit to protest, it will result in forfeiture of all cash and points earned in feature. Driver may not protest another driver finishing in a position behind them and may not protest same driver more than once per calendar year.