Author Topic: Revised Street Stock Rules  (Read 1151 times)


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Revised Street Stock Rules
« on: March 16, 2017, 09:00:17 AM »
Copied from CMS website:

Changes, additions, and edits since the last edition (2016), are annotated in bold, italic font.

Note, this is an entirely brand-new set of rules than were originally posted, this revised rules
set supersedes all previously posted and published rules.

USRA, IMCA, and NeSmith Stock Cars may compete at Central Missouri Speedway if their car is 100
percent USRA, IMCA, and NeSmith legal per the applicable rules set. Drivers from these sanctioning
bodies are responsible for adhering to these rules and bringing a copy of the applicable car-class
rules with them upon check-in/pill draw.

Minimum wheel base of 101” and must be stock for the body. 1” tolerance on wheelbase
from side to side but must not be less than minimum. 101” cars must remain stock on 3-link and
Panhard bar. Frame must match the body make (i.e. metric frame, metric body). Must be stock in
all aspects and remain unaltered. Maximum 3” Height Spring Buckets allowed to allow for weight
jack cup. Spring must remain in stock location and spring may not protrude above original stock
mounting position. Racecar must be same generation frame and body. (Exception is: 1980 or
newer Ford uni-body may be installed on Ford full frame, and shortened to minimum 108-inch
wheelbase. No tolerance.) Rear of frame behind rear axle may be replaced with two-inch by threeinch
steel tubing with .095-inch wall thickness. Original suspension mounts must remain intact,
unaltered, and in stock location. Uni-body cars must tie rear frame to front frame. Lead weight
may be added, but must be painted white and be marked with car number and bolted to the frame
in a safe manner. Weight cannot be mounted inside driver’s compartment above bottom of
window opening.

Four-point roll cage required. Cage must be frame mounted. Minimum of three bars in driver’s door.
Roll cage must be cross braced. Cage must be minimum of 1 ½” steel tubing with minimum wall
thickness of .095. Front and rear hoops are allowed. Aluminum and/or other soft metals are not
allowed. Roll bar connections must be properly welded. Roll bars within the driver’s reach must be
padded with an accepted material as determined by an official. Fire retardant material is highly
recommended. Installation and workmanship must be acceptable to officials. With helmet on and
driver securely strapped into the racing seat, top of driver’s head must not protrude above the roll
cage. May have two bars for protection in front of radiator. Must be located behind the front bumper
and within the confines of the body, and may be no wider than stock frame horns. Front horns may be
tied together. All front and rear bars must be inside the body. A minimum of one cross bar in top halo
of roll cage is required. Steel door plate with eighteen (18) gauge or forty-nine one-thousandths (.049)
inch minimum thickness metal must be securely welded the driver side door bars. Plate must extend
from the top door bar, to the bottom door bar, and must extend from the back of the seat to 6 inches
in front of the seat. Must be visible for inspection. A tow hook on both the front and rear is required.

Any model rear wheel drive American made production car. All cars and bodies must be stock
appearing. Roof and A & B pillars must be OEM style. Hoods must be OEM style, may be fiberglass
or aluminum. Rear deck lids must be OEM style, may be aluminum. Fenders, doors, and lower rear
quarter panels may be aluminum but must maintain original body line contour and remain stock
appearing. No slab side bodies. Cars may use aftermarket nosepiece and tailpiece but must remain
stock appearing. No wedge noses. Plastic front nose side allowed, must not extend past center of
front wheel well. Flare may not protrude more than 2” outward or above the standard contour of OEM
Fender. Rear of car must be completely enclosed. Minimum 1 -3/4" diameter tube front bumper will
be allowed w/aftermarket nose but must remain behind nose piece and attach at original position. No
mirrors or reflecting device of any kind. All glass, chrome, trim, moldings, etc, must be removed.
Windshield must be removed and replaced with a gravel screen or minimum of three (3) windshield
bars in front of driver. Gutting of inside panels and front inner fenders will be allowed. Must have
stock OEM or OEM style steel floor pan in stock location. Firewall may be stock or constructed of
minimum .049" steel and must be complete side to side. Trunk pan may be removed. Relief may be
cut for fuel cell and for engine set back only. All doors must be bolted or welded shut. A rear firewall is
required between the driver compartment and gas tank. Trunk lid must be secured. Interior on right
side of car may be enclosed but must have 12” x 12” trap door for inspection. Seat must be mounted
in front of the original front door post. Maximum 6 inches high spoiler allowed no wider than the body.
Spoiler may be braced on both ends and have one center brace no more than 6” high and 12” long
and must be triangular in shape. The maximum height from the ground to the top of the rear deck at
the top of the rear quarter panel is forty-three inches. *May run NeSmith bodies but must be complete
NeSmith body kits.

All racecars must be numbered with large legible numbers on both sides, on top and on the nose and
rear panels. Numbers on the sides of the race car should be in contrasting color from the body and be
at least four (4) inches thick and at least eighteen (18) inches high. Top numbers should be at least
four (4) inches thick and twenty-four (24) inches high. All cars must be neat appearing and are
subject to approval of officials to compete. By competing in an event, all drivers agree to comply with
the decisions of officials in this regard.

It is recommended that each car be equipped with built-in fire extinguishing equipment, but cannot be
of the dry powder type (must be Halon 1211 or equivalent). Drivers should have in their pit area as
part of their equipment, a fully charged dry chemical, Halon (or its equivalent) fire extinguisher.

Loose objects and/or weights are not allowed. Air bags are not allowed. Rear view mirrors are not

7) SEAT:
Factory-manufactured racing seats are mandatory, and must be acceptable to officials. Homemade
aluminum, plastic or fiberglass seats are not allowed. Must be properly installed and seat back cannot
be moved back further than rear edge of quarter post. High-back aluminum seats only. Full
containment racing seats are strongly recommended.

GM must run GM suspensions, Ford on Ford, etc. Tubular front non-adjustable all-steel, upper aframes
allowed. Speedway Motors 3 pc spindle will be allowed with OEM style steering arm. Front
lower control arms must be unaltered OEM or OEM style non-tubular, nonadjustable approved
aftermarket direct replacement. No aluminum parts. No bird-cages. No sliders. No traction devices of
any kind, no torque arms, no lift bars etc. One steel non-adjustable, unaltered shock per wheel. No
bump stops allowed (internal or external), no air, remote reservoir, bulb type, or Schrader valve
shocks allowed. No coil over eliminators. Adjustable weight jacks allowed, must be in original
centerline of spring tower; OEM upper A-frame mount may be moved or replaced with after-market
steel mount matching upper A-frame bolt on design; OEM or OEM replacement ball joints allowed.
For 1978-1987 GM mid-sized metric frames, OEM upper A-frame may be replaced using one-piece
after-market upper A-frame. Shock location may be moved and may go through center of after-market
upper A-frame. Front spring tower may be notched for shock clearance. Single hole shock mounts
only. Rear shocks may be mounted to install weight jacks. Only one single mounting point on the car
for rear shocks; additional mounting points not allowed. Front adjustable spring spacers are allowed.
Suspension mounts OEM and in OEM location. Rear trailing arms must be non-adjustable OEM or
non-adjustable approved aftermarket direct replacement. Trailing arm bushings must be installed and
must be OEM type. Lower trailing arms must be at least 19” center to center and the same length.
Lower trailing arm mount on rear axle may be no more than 3 ½ inches from bottom of axle housing
to center of bolt and must be same height side to side. Upper trailing arm mount may be no more
than 3 inches from housing to center of bolt. Front upper and lower trailing arm mounts must be in
stock OEM unaltered location. Sway bars OEM and in OEM location and non- adjustable on rear. No
suspension travel limiting devices (chains, straps, etc).

Must be OEM and remain within original bolt pattern for type of frame used. May be modified to suit
driver, but must remain on left side of cockpit (no center steering). Removable steering wheel and
steering quickener allowed. Plastic couplings are not allowed. OEM rack and pinion steering allowed
if car was originally equipped. No aftermarket rack and pinion units.

Must be fifteen (15) inches in diameter and eight (8) or 10 (ten) inches in width. Tire must match
wheel width. Must be reinforced steel only. A steel bead lock may be used on the right rear wheel
only, and may be mounted on the outside of the wheel so long as it does not add over three-quarters
(3/4) of an inch to the overall width of the wheel. Homemade mud caps are not allowed. Wheel covers
are permitted on right side wheels only. Inner mud plugs are permitted. Spacer or adaptor, offset
wheel or a combination of the two is permitted, but may not exceed two (2) inches total offset per
wheel. Three tabs of no more than two (2) inches long each may be welded onto the wheel for
mounting of mud cap. Bleeder valves are not allowed. No Wide-5’s.

11) TIRES:
American racer G-60, Hoosier G-60 IMCA modified tires, Hoosier A-40 or 10 inch Hoosier
asphalt take offs (1 0.0 / 27.0 0-15). Tire must match wheel width. May re-groove tires. Tires must
durometer minimum 55 hardness. Softening is not allowed. Solvents of any kind are not allowed.
Altering tires with any components or chemicals, which alter the manufacturer’s baseline-settings
of the tire, is not allowed. Grooving and/or siping is permitted. All sidewall markings must remain
visible at all times. Buffing or removing of the compound designations is not allowed. All tires must
“Cold” durometer a minimum of 55 prior to prerace inspection, no tolerance allowed. After any race
the tires must “Hot” durometer 50 or above. Any tire reading below 50 will result in a disqualification
for that race and will be subject to tire testing. Any tire “Hot” that durometers higher than 60 will be
subject to tire testing. Any tire not meeting the durometer rule reading is subject to disqualification.

Must be operating on all four wheels and must lock up all four wheels during inspection. Must have
caliper and rotor on all four wheels. Electronic brake actuators are not allowed. Must be OE operative
four-wheel drum or disc brake combination. Stock rotors only. Scalloped rotors are not allowed.
Rotors may not be lightened. Floating brakes are not allowed. Brake lines must be outside frame rails
and visible. Brake shut-off and/or pressure sensitive devices are not allowed. One proportioning
device (front to rear only) is permitted. Must maintain minimum OEM dimension for hubs, rotors and

Aluminum water pumps are permitted. Cooling system may be modified. Sprinkler systems are not
allowed. One (1) radiator is permitted and must be mounted in front of engine. Overflow tubes must
be directed to the ground, between frame rails. Accumulators and Accu-sumps must be mounted in
the middle of the racecar or behind the driver, but not on door bars. Top flow air cleaner housings are
permitted. Cold air boxes and/or air cleaner ductwork is not allowed. Marine-type engine components
are not allowed.

Must be mounted in such a way as to direct spent gases away from cockpit of vehicle and away from
area of possible fuel spillage. Use of mufflers is recommended. ‘Zoomies’ and/or 180- degree
headers are not allowed. Exhaust pipes must extend to and connect with one (1) collector at least
four (4) inches long. Must remain dual exhaust. Crossover or ‘Y’ pipes are not allowed.

GM Performance Parts (GPP) factory-sealed CT400 Chevy small block crate engine (Part No.
88958604): includes 8-quart circle track oil pan with dual kick-out design, valve cover breather kit,
open-plenum high-rise intake manifold, 1.5:1 -ratio aluminum roller rockers, forged steel crankshaft,
hypereutectic pistons, 23° Fast Burn aluminum heads and special "kool nut" rocker arm design. Must
be unaltered and sealed from factory at appropriate points (intake, head, timing chain cover and oil
pan) with approved GPP break-off bolts. Any altered, damaged or missing GPP break-off bolts will
result in driver being disqualified from that event, loss of all track points accumulated up to, and
including, the date of the offense, a $1,000 fine and a one-year suspension from all events. May
utilize one (1) Holley 4-barrel carburetor. Use of a spacer between carburetor and intake is optional,
but must be no more than one (1) inch thick if used and may not be throttle bore adjustable. Aerosol
carburetors are not permitted. Any driver running a “Standard” engine with a “Crate” sticker will be
disqualified. Bert, Brinn, and Falcon transmissions are allowed on crate motor only. Must utilize a
maximum 6800 RPM rev limiter. Rev Limiter may not be within reach of the driver while in cockpit and
must be easily accessible to officials at any time.

Steel blocks only. Must be able to be used in a conventional passenger car without alteration. 23-
degree cast iron heads only. Aluminum intake is allowed. Headers allowed. No Tri- Y headers. Tip of
number one spark plug must be even or in front of installed upper ball joint. Oil pump must be in stock
location and OEM. No dry sump systems. Exhaust system and /or mufflers must be mounted in such
a way as to direct spent gasses away from the cockpit. No lightening or external machining of block
or heads.

Rear ends may be locked. 8” or 9” Ford may be used on all car makes. Floater rear-ends are allowed.
No traction control devices. No ratchet rear ends or torque dividing differentials. No cambered rear
ends allowed. Axle Tubes must be OEM and same diameter and length side to side.

Minimum 2” diameter drive shaft retained with a steel safety strap. Must be painted white and made
of steel. A loop is required and must be constructed of at least one-quarter (1/4) inch by two (2) inch
solid steel. Loop must be mounted no more than six (6) inches from the front of the drive shaft tube.
Alternatively, two (2) loops of one-quarter (1/4) inch by one (1) inch solid steel fastened to cross
member are allowed. Yokes must be made of steel.

Three or four speed only with all forward and reverse gears functional. No direct drives. Automatic
transmissions allowed with gate valve. “In and out” boxes, five-speed transmissions, and quickchange
devices are not allowed. No aftermarket transmissions. Car must move under its own power.
Automatic transmissions must remain in OEM stock appearing automatic case with a functioning
stock appearing pump. Original bell housing must remain. Must have approved scatter shield or
blanket. Scatter shield may be constructed of one-quarter (1/4) inch by three (3) inch steel, two
hundred seventy (270) degrees around flex plate or flywheel. Bert, Brinn, and Falcon transmissions
are not allowed.

Car must have a workable clutch or gate valve. Mini clutch allowed.

Cars utilizing engine option #2-Standard Engine must use 2-barrel carburetor. No more than 500
CFM. Maximum 1 -11/16” throttle bore maximum. Carb must pass top and bottom “no go” gauges.
Holley’s OK. Sealed crate engines may use 4-barrel as stated in crate engine section. Maximum oneinch
spacer under carburetor. No aerosol type carburetors allowed. No remotely adjustable
spacer/adapter plate between carburetor and intake manifold.

Must be securely mounted and covered. One (1) 12-volt battery only (no 16-volt batteries). Voltage
converters are not allowed. Must be in a marine-type case and mounted in trunk area. Positive
battery posts must be covered.

Aftermarket or OEM Distributors allowed. No adjustable timing control or magnetos allowed. One
MSD Box Allowed. Aftermarket ignition module and coil allowed. Track may confiscate and exchange
MSD box at any time. Magnetos and/or crank-triggered ignitions are not allowed. No more than one
(1) coil may be used. Kill switch required within easy reach of the driver. The switch must be clearly
marked “off” and “on”. Ignition box must be out of reach of driver. Digital gauges are not allowed.
Must have visible numbers on back of car. Refer to CMS General Track Rules for additional
information. If you do not have this booklet, ask for one at the registration/pill-draw tower.
« Last Edit: March 16, 2017, 02:19:08 PM by bartlett »