GENERAL RULES:

Pure Stock is stock division for the budget minded racer. If you have the financial means or
desire to modify your car outside of the following rules please consider racing in the appropriate
division. Minimum age requirement is 14 years of age – Ages 14 -17 must have a notarized
release form signed by their parent or legal guardian and a copy of birth certificate on file with
I-37 Speedway.
All drivers are required to have a working raceceiver.

DRIVER RESTRAINT/SAFETY:

All Safety Equipment is Subject to Track Inspection and Approval, applies to all times a car is on
the track including packing, both driver and passenger.
Snell-Rated Helmet in Good Condition, SFI-Approved full fire suit, fire retardant gloves, shoes
and neck brace (or head and neck restraint system).
Minimum three inch wide SFI-Approved Five Point Safety Belt assembly required (2 inch with
head and neck restraint system) and must mount securely to main roll cage with 7/16 bolts.
Fire-resistant roll bar padding required on any part of roll cage driver or passenger may contact
while buckled in.
Aluminum high back racing seats required, (Driver and Passenger) must be securely mounted
with a minimum of four 3/8 bolts.
Seat mounting must be integrated into roll cage design and be in stock OEM seating location,
seat cannot be bolted to floor pan.
Minimum 16 inch X 20 inch driver’s side window net is required and must be mounted to roll
cage so that latch is on top and front of window opening. (Also required on passenger side if
passenger is in car).
Fire extinguishers are mandatory in the driver’s compartment within the reach of the driver when
buckled in, must have a fill level gauge.
Recommend: Safety Belts to be no more than two years old.

FRAME:

Any American made OEM 1964 or newer full frame or unibody full bodied rear wheel drive stock
passenger car, S -10 or Ford Ranger Pickups, Station Wagons must be metric framed.
No Camaros, No Firebirds, No Trans AMs, No Mustangs, No Corvettes, No Convertibles, No
Sports Cars or No Front Wheel Drives allowed. GM to GM, Ford to Ford, Chrysler to Chrysler.
Frames must be OEM Stock, no cutting, shortening, lengthening or modifying is allowed.
Minimum wheelbase of 108 inches. (+ or – one inch) Frame may be X-braced.
Unibody cars may tie front frame to rear frame, may plate top section of rear unibody frame.
Full frame cars may replace rear frame section with minimum 2 inch x 3 inch x 095 steel tubing
from 1 inch behind factory shock tower and be must be same length as material removed, shock
tower must remain stock be in stock location and be full and complete.

ROLL CAGE:

Minimum of a four point roll cage with continuous hoops must be constructed of magnetic steel
tubing of no less than 1.5 inch OD x .095 inch wall thickness and must be welded to OEM
frame. Main roll cage and halo must be a minimum of 1 inch above drivers head with helmet on
and buckled in car.
Main cage rear hoop must have a minimum of one horizontal bar and one diagonal bar from top
of hoop to bottom of down bar. Main cage front uprights must tie together with a minimum of
one horizontal bar. Front left and right kickers required from main cage to in front of engine.
Rear left and right kickers required from main cage to rear frame section.
Front and rear loops allowed. All welds must be complete.
Door Bars:
Minimum of 3 driver’s door bars 1.5 inch OD x .095 inch wall thickness, parallel to frame and
perpendicular to driver and a minimum of 2 horizontal passenger door bars (passengers are
allowed, but 3 bars also required on passenger side if passenger in car​).
Must be constructed with a minimum of 3 vertical bars from frame to top door bar in an
intertwined fashion to strengthen door bar system.
Driver’s side steel door plate of 18 gauge or 0.0049 inch minimum thickness is required, plate
must extend the full length of the door, may be welded into door bar system design. (Also
required on passenger side if passenger in car). All welds must be complete.

BODY:

Bodies must be stock appearing; panels may be replaced with stock appearing aluminum or
steel aftermarket panels (18 or 20 gauge). Example: Five Star or Performance Bodies stock
replacement panels. NO spoilers (even if factory equipped), no wings, no skirts, no air scoops,
or anything that alters stock appearance. Bodies cannot be moved from the original rubber
bushing location no more than + or – 1 inch. Rear of car must be covered from top of trunk to
top of the bumper. Can use plastic rear piece or sheet metal.( This is Mandatory) You can install
plastic skirting on bottom of side panels.
Upper front windshield visor is allowed not to exceed 7 inches in width.
Doors must be bolted or welded shut, sunroofs and T-tops must be reinforced and enclosed.
All glass, plastic, upholstery, lights, mirrors, and trim must be removed.
Front inner fender wells may be removed.
Car must have A, B or C pillars. Front and rear firewall, floor pan must remain stock be full and
complete and remain in stock location, floor pan may be cut for roll cage installation clearance
only, all openings must be covered with 20 gauge steel to isolate the driver. Any rusted out or
partially missing floor pans may be replaced or patched with 18 gauge steel.
Front and rear outer fenders may be cut for wheel and tire clearance. No excessive trimming of
fenders or hoods allowed, must maintain stock appearance.
No enclosed interiors or decking allowed, no part of dash can be more than 28″ inch from back
edge of the center of the hood. Trunk floor may be removed.
Racecar and body should be maintained in such a manner as to keep a presentable
appearance. Inner skin may be removed from hood, trunk lid and doors.
Hood and trunk must be secured with hood pins, no holes allowed in hood except for hood pins.
Must start each race night with all body panels including hood, trunk lid, fenders, nose or tail
piece and bumpers. Cars with floppy or loose body parts considered as a safety hazard will not
be allowed to compete until requested repairs are made.
A minimum of three vertical windshield bars are required in front of driver, must be solid steel
bars minimum 3/8” OD (also required on passenger side if passenger in car) and must extend
from upper windshield flange at roof to lower windshield flange at cowl.
No roof rake, must remain as OEM produced.

NERF BARS:

One Nerf bar per side allowed not to exceed 1 ½ inches from body line.
May be constructed of square or round mild steel tubing maximum of 1 ½ inch OD.
Must be rounded or closed and turned back toward body with a 90 degree angle on both ends,
with no sharp edges.
Performance Bodies type Lexan Decal Protection OK, must be mounted be flush to body.
Nerf bar or decal protection may not extend past front edge of door and must end in front of rear
wheel opening.

BUMPERS:

Stock type front and rear bumpers with straps to prevent hooking.
Fabricated pipe front and rear bumpers will be allowed on cars with aftermarket nose and tail
pieces. .095 round tubing with minimum of 1 ½ diameter and maximum of 1 ¾. Tubing must
wrap around side of body panels. No straight cut tubing allowed. No sharp edges.
All support piping must be behind nose and tail pieces, support may extend past front frame
horns but no bracing allowed outside front frame horns.
NO CATTLE GUARD FRONT OR REAR BUMPERS​ – Subject to Track Inspection and
approval.
Mandatory:​ Must have a visible chain loop for wrecker hook up on front and rear of car.

ENGINE:

Any OEM factory production small block cast iron V-8 engine with a maximum of 364 cubic inch
displacement. Stock replacement 2 or 4 valve relief pistons, no lightweight pistons or wrist pins,
OEM or OEM replacement 5.7 connecting rods only, aftermarket rod bolts allowed.
Stock OEM or OEM standard weight replacement cranks, minimum crankshaft weight 48 lbs.
No bull nosing, lightening holes or knife edging allowed. Maximum stroke of 3.48 inches. Engine
balancing OK.
No splayed main caps. Engine bolts may be aftermarket. Aftermarket harmonic balancer OK.
Maximum engine cranking compression is 160 psi. For testing the engine rotating assembly will
be “spun” by the starter, for five “hits” on the cylinder being tested. Aftermarket oil pans OK,
recommend a 1” inspection plug. The plug should be located on the left hand side
approximately
2” down from the pan rail and in line with a connecting rod assembly that is convenient to look at
when the pan is installed in the car.
No type of windage trays allowed. OEM type timing chain system only, double roller OK, No
gear drives or belt drives. Aluminum pulleys and serpentine belt system OK
Cast iron water pump, may be aftermarket. Aftermarket power steering pump with integrated
tank OK
Motor must be in OEM location; solid motor mounts allowed but must be in OEM location, NO
tolerance .
**602 GM Crate engine is allowed with no modifications. Must be sealed with Crate engine bolt
kit. Must run 2 barrel 4412 carb on crate motor option.
Cylinder heads:
OEM production unaltered cast iron cylinder heads with a minimum 72cc combustion chamber
or E Force SBC 76cc Straight Plug Cast Iron Heads can be used. Part #175769. Vortec or
double hump OEM heads not allowed. 305 heads allowed on 305’s only, 305 heads not allowed
on 350’s.
Maximum 1.94 intake valves and 1.50 exhaust valves, Exception: 1.630 exhaust valves allowed
on Chrysler Engines. Must be all 1.50 or 1.630 valves ,No mixing of sizes. Heads may be flat
milled for surfacing reasons only, no angle milling.
Valve spring OD diameter must not exceed 1.250 inch (+ or – .015 inch).
Guide plates, 3/8 X 7/16 screw in studs and poly locks allowed, pinning of OEM studs allowed.
1.5 or 1.6 Stamped Steel Rockers on GM & Chrysler, 1.6 on Ford (No full roller or roller tipped
rockers allowed).
No grinding of any kind allowed on heads, no gasket matching, no porting or polishing.
Aftermarket valve cover with breather tubes OK. Oil diverters are allowed under valve covers.
Intake Manifold:
Unaltered cast iron or aluminum OEM intake manifolds only. No bowtie, marine, or high-rise
intakes.Edelbrock #2101 Performer Intake allowed. No internal modifications of any intake
permitted, No deburring or grinding allowed.
Must have a ¼ inch accessible vacuum port on intake for Tech.

CAMSHAFT AND LIFTERS HYDRAULIC:

Camshaft and hydraulic flat tappet lifters only, no hydraulic OEM roller lifters. Rhoads, Variable
Duration or “Bleed Down” lifters are not allowed.
Maximum valve lift of .450 inch measured at steel retainer.
Solid lifter will be used at tech for testing purposes. Maximum push rod length of 7.800 inch.
OEM firing order cannot be changed thru cam design. GM firing order 1-8-4-3-6-5-7-2.
Engine must have a minimum of 15 inches of vacuum at 1000 engine RPM. No tolerance
No vacuum canisters allowed, brake booster will be disconnected and capped during time of
vacuum inspection.

CARBURETOR:

One unaltered 500 CFM Holley 4412 2-Barrel, is subject to be checked with go-no-go gauge.
Removal of the choke flap is the only modification allowed, choke horn must remain, cannot be
removed.
Mandatory: ​Must have two throttle return spring. An adapter/spacer will be allowed under the
carburetor, maximum 1” thickness. No 4412 Ultra XP Carburetors will be allowed.
No GM Q/Jets, GM Spread Bores, Ford Motorcraft or Chrysler OEM 4-Barrels allowed.
No fuel injection. Maximum air cleaner of 14 inches diameter x 4 inches height. No top flow style
air cleaners allowed.
No type of RAM Air or Forced Air Induction will be allowed.

FUEL:

Pump Gas, Aviation Gas or Race Fuel with no additives, no methanol or smell enhancing
additives.
Mechanical fuel pump must be stock mount pushrod activated; aftermarket manual type pump is
OK. (Example: Carter, AC, Holley).
Electric fuel pumps are not allowed.
Fuel lines which pass thru driver’s compartment must be enclosed in metallic conduit or pipe
from front firewall to rear firewall.

FUEL CELL:

Racing Fuel Cell is required, maximum capacity of 22 gallons and must be enclosed in a 20
gauge steel container.
Must mount between rear frame rails and be properly supported and protected.
A minimum of two solid steel 2 inch in X 1/8 in thick straps are required around entire fuel cell.
Fuel cell may not be lower than rear frame rails.
Fuel Cell may also be mounted on top of stock trunk floor pan and be secured with 1 inch X 1/8
inch straps or 3/8 inch steel cable.
Fuel cell or tank must have a one way check valve to prevent fuel leakage in event of roll over.
No plastic boat tanks.

EXHAUST:

Stock cast iron exhaust manifolds only, No center dump (ram horns)of any size, marine, or tubular steel type exhaust manifolds. No headers. Exhaust pipes must turn down or extend past driver’s compartment. No porting, acid dipping or modifying manifolds of any kind allowed.

TRANSMISSION/DRIVESHAFT:

Only OEM production transmission allowed, with the exception of No 5, 6 speed or overdrive
transmissions allowed.
All forward gears must be in working order on all transmissions, with a neutral and working
reverse.
No aluminum or light weight flywheels.
Automatics​ Must have a fully operational torque converter with a minimum of 10 inch
diameter with no modifications.
No “Dummy” converters. No Direct Drive automatic transmissions allowed.
Automatics must pass following inspection, with engine at idle, and brake applied, transmission
must shift from “neutral” gear to “reverse” gear and from “neutral” gear to “low “gear, without
causing engine to stall. Race car must remain stationary during such shifting and testing.
SFI Rated flex plate required, Scatter shield recommended on all automatic transmissions.
Transmission cooler OK, if mounted in driver’s compartment must be shielded to protect driver
from fluid in case of leak.

STANDARDS:

Must have a minimum 10.5 inch clutch, pressure plate, OEM or OEM replacement steel
flywheel. Standard transmissions must have a ¼ inch steel plate covering the bell housing 180°
over the sides and top of clutch assembly or explosion proof steel bellhousing. Aftermarket
clutch pedal, hydraulic master cylinder, and throwout bearing OK. Car must be self-starting.

DRIVESHAFT

All drive shafts must be steel with a minimum diameter of 2.5 inch, painted white with the car
number.
Drive shaft must have a 360 degree safety loop constructed of min 0.25 inch thick by 2 inch in
width and mounted within 6 inches of the front u-joint. No chain loops allowed.

SUSPENSION:

Front and rear suspension must be stock for that make and model with no modifications.
No alterations to any part of the suspension will be allowed.
Can use any Non Adjustable tubular type upper control arm.Must use steel cross shaft.
Cannot relocate or move upper A-arm mounts on frame.
Ball joints must be OEM replacement. No extended, low friction or rebuildable type ball joints.
Upper and Lower A-Arm bushings may be replaced with OEM rubber type only.
No offset, spherical or low friction bushings allowed front or rear.NO SCREW IN BALL JOINTS
ALLOWED.
Aftermarket steel springs allowed, minimum 5 inch OD springs, rear springs may be of single or
double pigtail design and fit stock spring perch on rear end, may not exceed 14 inches in free
height.
No adjustable spring spacers or adjustable weight jacks of any kind, Leaf spring cars may use
non adjustable lowering blocks, must use OEM replacement rubber style bushings in front and
rear springs, rear sliders not allowed. No bump stops of any kind allowed.
Sway bars allowed, must be OEM design, with equal height/spacing on each side, no preload.

SHOCKS:

OEM stock mount replacement shocks only. No air shocks. No rebuildable or revalveable
shocks. No adjustable shocks. No GAS shocks.Must be welded or factory crimped ends.Shocks
must have stock type rubber ends, no screw on type rod ends, must be mounted in stock
location on frame. Shocks must fully collapse and extend. Shocks can be claimed by track or
Pure Stock Driver (Must have raced at least 3 consecutive races at I-37)for $75 per shock at
any time

REAR END:

Rear-end must be stock OEM for make and model of car. OEM Brackets in STOCK location.
Control arms cannot be lengthened or shortened. Any gear ratio is allowed as long as the
housing doesn’t have to be altered to accept. Rear end must be locked. Mini spools OK. No
limited slip or posi-traction allowed. Aftermarket axles are allowed.

STEERING:

Must use stock OEM gearbox or OEM stock replacement for make and model.
May use aftermarket steering shaft, related components and quick release steering wheel
disconnect.
Quick Steer is optional.
Drag link, tie rods and all other steering components must be OEM replacement for make and
model.
Bolt on Spindle Savers OK.

BRAKES:

Aftermarket brake pedal with single master cylinder allowed,does not have to be in stock location. Only one master cylinder allowed and can be aftermarket.No brake bias adjusters.

Car must have a minimum of 3 wheel brakes in working order at all times, right front shutoff valve is allowed. RF brake must be operational if valve is in open position.

For safety purposes, rear disc brakes optional, rear disc brakes must be steel components only; caliper must be of single piston type only.

WHEEL/TIRES:

Wheels
Any 15 inch diameter X 8 inch wide steel wheel permitted. 5/8 studs and 1 inch lug nuts are
required.
Maximum 1 inch wheel spacers are allowed, minimum of 2 available threads must be visible on
stud after tightening of lug nut. No beadlocks, adaptors or tire screws are allowed.
Tires
Hoosier G60, American Racer KK704, Southwest Speed Dirt 60, 60 Series Street Tires or 8
Inch Asphalt takeoff are allowed. Grinding, siping and grooving allowed, No chemical softening
or conditioning.

ELECTRICAL/BATTERY:

The car must have a battery disconnect switch located outside the car and easily accessible to
emergency track personnel and clearly label. If the car is equipped with a working alternator the
switch must also disable alternator.
All cars must have an ignition switch and must be clearly labeled and accessible form outside of
car for track personnel. Only one 12 volt battery is allowed.
Battery must be in sealed enclosure and securely mounted if in located driver’s compartment,
recommended to be trunk area and must be between and above frame rails, subject to track
safety inspection and approval. Aftermarket Starter OK, must be block mounted.

IGNITION:

OEM Stock type distributor in stock location only, can be HEI or points type.
Aftermarket OEM style replacement components OK
All components of HEI distributor including coil must be internal, points ignition may run external
coil.
NO traction control devices of any kind. Excluding spark plug and external coil wires, maximum
of 2 wires connected to distributer one switched positive for ignition and one for tachometer.

RADIATOR/ENGINE COOLING:

Only one radiator is permitted in stock location, Aluminum radiator OK.
Radiator protection is required, must not extend outside frame horns or forward of hood.
Radiator core support may be removed and alternate radiator support fabricated.
Water pump mounted fans only, spacers allowed, No electric fans.

WEIGHT/BALLAST:

Minimum Weight – 3200 lbs.​ with driver. All ballast weight must be securely fastened.
Must be painted white and include car number. Ballast weight cannot be mounted inside driver’s
compartment. Maximum of 52% rear percentage to be checked after race. If after a race
upon inspection a car w/ driver is over 52% rear percentage the driver will be allowed to
address collected mud on the car and get one chance to rescale. (appointed tech
inspector will watch removal of mud from car).

CAR NUMBERS:

Numbers must be a minimum of 24 inches in height and 4 inches in width; must be on both
sides of car and positioned on roof so it can be read from passenger side of car.
All numbers must be of a contrasting color and be easily read from scoring tower.
Recommend one 6’’ number on front and rear of car to aid in line procedures