Street Stock

2017 Street Stock Rules
IMCA Stocks are also allowed to race with Street Stocks

A. Any U.S. manufactured (Ford, GM, Mopar) full bodied rear wheel drive passenger cars 1960 or newer. No X -frames.
B. Commercial vehicles, convertibles, sports cars, Novas, Mustangs and Firebirds NOT ALLOWED.
C. Wheelbase will be 107″ minimum. Uni-body cars will be allowed to tie frames together. No after market bodies. Bodies must be OEM steel, or per factory parts. Uni-body frames cannot be shortened.
D. Stock floorboards for frame used must remain stock.
E. Body must match year and make of frame. Wheelbase + or – 1″ of stock.
F. Motors must be Ford to Ford, Chevy to Chevy, Mopar to Mopar on frames.
G. Plastic nose pieces allowed (must match manufacturer).
H. Number one spark plug on motors may not sit behind upper ball joint.
I. Firewall may be beat back or moved to clear distributor, headers and motor. Front OEM firewall may be replaced using steel fabricated firewall ,18 gauge or minimum 0.049 inch thickness. Top of firewall can be no further back than 12 inches from the back of engine block , measured horizontally .Bottom of firewall can be no further back than rear of oval body mount frame hole.
All holes in firewall and behind drivers seat must be sealed.
J. Decking of interior OK, but must be sheet metal or aluminum. Stock dashboard may be removed.
K. Hood scoops or holes in hood for air cleaner OK.
M. Spoilers are legal. 5″ tall maximum.
N. All body molding must be removed (door handles, trim, etc.).
O. No McPherson strut front ends or frames of any type.
P. Fender wells may be trimmed for tire clearance.
Q. May not chop or lower roofs on bodies and must retain stock dimensions.
R. Inner fender wells (front) may be removed. Radiator support brackets can be built. Hood and trunk deck can be gutted. Hood and trunk deck pins OK.
S. Leaf spring cars may use shackles (no sliders). Leaf springs must be steel and use stock mounting brackets. Lowering blocks allowed (max 3″). No adjustable lowering blocks allowed.
T. Bumpers may be stock, or round tubing (1¾” max) or square tubing (2″ max). If using square or round tubing bumpers can be only as wide as body. All open ends must be capped. No ladder bumpers allowed. Maximum of one hoop on top and one hoop on bottom of rear bumpers. Front bumpers will be allowed one hoop on top of bumper and may protrude past nosepiece if one is used. Bumpers must look clean. All other bracing would remain behind nosepiece. NO COW CATCHERS. Bracing from outside of front bumper back to frame recommended.
U. Trunk floor board may be removed.
V. I-Stock bodies must run Street Stock legal motor and transmission. No couplers. Weight jacks must be welded in place.

You may only run one carburetor on intake.
A. Holley #4412, 1 two barrels, only, NO Jets on the side of carbutor. NO unaltered.
B. Carburetor spacer/adapter is allowed, but must not exceed 1¼” total thickness including gaskets.
C. Carburetor must be stock and unaltered with only one exception: circle track floats may be used. Holley must have choke horn attached.
D. OEM carburetion not to exceed one (1) 2-BBL. GM cars must run Rochester carb. Ford cars must run Motorcraft or Autolite carbs only! Chrysler cars must run Carter carb.

A. Only 283, 302, 305, 307, 327, 350 blocks can be used for Chevrolet. No big blocks. OEM only.
B. Only 260, 289, 302 and 351 blocks can be used for Ford. No big blocks. OEM only.
C. Only 273, 318, 340 and 360 blocks can be used for Mopar. No big blocks. OEM only. No hemis.
D. All casting numbers must remain on blocks. No side bolt main blocks allowed.
E. No Pontiacs, Oldsmobile, Buick, Rambler, Studebakers, etc. motors. We realize some of these cars came with Chevrolet motors. Chevy motors will be legal.
F. NO 4-cylinders allowed. No V-6’s allowed. No in-lines. V-8’s only.
G. Again: only Ford, Chevy or Mopar engines are allowed.
H. Mopar = Chrysler, Plymouth and Dodge.
I. Ford = Ford and Mercury.
J. Chevy = Pontiac, Buick, Oldsmobile as long as they are Chevrolet engines.
k. No 400 small block or big block crankshafts allowed! This goes for Ford, Chevy or Mopar.
L. Mopar = Chrysler, Plymouth and Dodge. 370 cubic inch maximum.
M. Ford = Ford and Mercury. 360 cubic inch maximum.
N. Chevy = Pontiac, Buick, Oldsmobile as long as they are Chevrolet engines. 368 cubic inch maximum.
O. No tolerance on cubic inch.

A. Flat top pistons only. No forged of any kind. Decking block okay. Two eye piston ok.
B. OEM blocks only. No Dart or after market blocks. No aluminum.
C. Stock or circle track pans allowed. No dry sumps.
D. Fluid dampner harmonic balancers are allowed.
E. Stock OEM cast iron or OEM aluminum intake is required. No marine or Bowties. No after market. No tall intakes. No hi-performance.
F. No Brezinski, porting, polishing, acid dipping, or anything similar allowed. No hi-rise.
G. After market starters okay. Must mount in front of bellhousing.
H. Power steering pump must mount in front of engine.
I. Steel side engine mounts may be of the 45 degree style or stock style.
J. Engine mid-plate is allowed and may be aluminum.
K. Any brand of air cleaner allowed.
L. Stock OEM rods. Balancing okay. No aluminum. Chevy = 5.7″ length maximum rods. No floating pistons.
M. OEM cranks only. Steel or cast. Balancing okay. No splayed main caps. No after market cranks.
N. 3.48 stroke maximum for Chevy. Balancing okay.

A. Hydraulic lift cams or solid lift cams only.
B. No roller cam or lifters.
C. No reverse rotation cams or motors. OEM rotation only.

A. No porting, acid dipping, polishing. Screw-in studs or guide plates allowed.
B. Stock diameter springs only for heads used. Stock type rocker arms. Any ratio. Ford rocker arms on Chevrolet okay. Roller tip OK.
C. Roller rocker arms are ok.
D. Poly-locks are allowed.
E. No stud girdles.
F. Any breather/valve cover configuration/composition is allowed.

A. Cast iron heads only. Vortec heads ok Casing # 906 and 062. Aluminum intake for a voctec head must run the following numbers only and must be stamped IMCA, ELDERBROCK edl2716. No aftermarket. No angle plugs. Exception: S/R torquer heads OK.

A. Any cast iron head. OEM Ford heads only.
B. No Boss or after market heads of any kind. Cleveland 2V heads OK.

A. Any cast iron head. OEM Mopar only.
B. No after market heads of any kind. W-2 heads OK.
C. Mopar can use the rocker arm bars. OEM only. No roller tips.

A. All cars must have ignition switch clearly labeled.
B. Ignition switch must be located within reach when standing outside the car (easily accessible to emergency personnel).
C. Stock or stock style ignition only. Ford may use Motorcraft or FoMoCo, including box. Mopar may use Mopar, including box. HEI legal on Ford or Mopar.
D. HEI must remain in one unit, no external coils allowed, unless you are using dual or single point distributor.
E. MSD or any module may be used as long as it fits inside the distributor with no alteration. Vacuum advance may be removed and the pick-up coil locked.
F. MSD, any brand, or GM electronic boxes are not allowed. No magnetos.

A. Only one 12 volt battery is allowed.
B. Must be securely mounted in trunk
C. Battery may be charged by an alternator. Cannot be in driver’s compartment.

A. Headers OK. No 180 degree, no over the top, no step headers, no zoomies. 3″ maximum collectors. 1 5/8″ maximum tubes.
B. Cannot use adapters to butt headers to heads.
C. Stock cast iron exhaust manifolds must be 305 manifolds.
No ram horn-type exhaust manifolds.

A. Only one radiator is allowed. It may be aluminum. Radiator must be mounted in front of engine.
B. Racing radiator cap is allowed.
C. Electric cooling fans are okay.
D. May not have water outlets to spray on radiator. Catch cans required.

Gasoline only. No oxygenated or other performance enhancers! No alcohol or nitrous.
A. No electric fuel pumps. Only stock mount push rod activated Holley and Carter style allowed.
B. No bypass fuel systems, pressurized, or return lines allowed. No regulators of any type.

A. Maximum 22 gallon fuel cell.
B. Fuel cell with a roll over valve is required. Must be securely mounted inside trunk area only, must be between frame rails, and must be totally enclosed from the driver compartment. A minimum of two (2) fuel cell straps required to secure fuel cell.

A. Any OEM automatic or standard transmissions are allowed. Transmissions must have at least one forward gear, and reverse gear must be in working order. 10″ minimum working converter (steel only).
B. All standards must have bell housing made of ¼” thick steel or cast iron (if no scatter shield) and cover 180 degrees over the sides and tip of the clutch assembly. Slave cylinders or hydraulic throw out bearing okay. 10″ minimum clutch assembly (steel only).
C. 3, 4 or 5 speed manual transmissions only, OEM only. No Bert or Brinn type transmissions allowed.
D. No after market transmissions.
E. Quick change transmissions or transmission adapters for gear change are not allowed.
F. Car must be self-starting and have working neutral, reverse, and forward. No mini-clutches.
G. Transmission fluid coolers are allowed.
H. Cars MUST idle in all gears.
I. No direct drives, couplers, valved pumps, or bleeder style valve bodies.

A. Drive shafts must be steel, and must be painted white or silver or fluorescent orange.
B. Must have steel drive shaft loop (360 degree) connected to the frame located within 6″ of the front drive shaft u-joint.
C. Minimum size is 2″ x 1/8’.

A. Rear end housing may be stock 7.5″ GM 10 bolt. Bracing optional. Snouts on end of 7.5″ rear end can be modified to accept 9″ Ford axle. After market axles, studs, and mini-spools are allowed. No posi-trac, limited slip style rear ends. Rear end axles must be locked together at all times. C-clip eliminators are allowed. Cups may be placed on housing for springs only, but must remain in stock location.
B. Any gear ratio OK.
C. Bolt pattern on the axle/drums or rotors may be changed. No full spools, Gold Track, or aluminum spools of any kind! Stock width unless using Ford axles. If Ford axles are used, rear-end must not be narrower than stock nor more than 3″ wider. No Detroit lockers.
D. Floater rear-ends allowed. 9″ Ford or 8.5″ rear-ends allowed, but must put all mounts in stock location. No quick change.
E. No adjustable mounts or adjustable holes in mounts.

A. After market pedal and cylinder for clutch OK.
B. Rear brakes must be drum or disc up to 12″ disc brakes. Steel only! Hats and steel rotors are legal on rear ends ONLY Hats must be steel. No single phase rotors allowed.
C. A proportioning valve may be used, but must be installed out of the driver’s reach. No fluid controlled valve of any type within reach of the driver.
D. Minimum of three working brakes is required. If using three brakes, the fourth brake components need not be present. Spindle must remain unaltered.
E. Cooling holes may not be drilled in any brake components.
F. No aluminum brake components allowed.
G. After market gas pedals OK.
H. After market brake pedal and master cylinders ok

A. Quick release steering wheel is mandatory.
B. Quick steer is optional. No chains or sprockets allowed in the steering system except D&M quick steer.
C. Steering left of drive train only. This means driveshaft!
D. Bump steer cannot be adjusted. Center link, inner tie rods, outer tie rods, or sleeves can not be altered, and must remain stock for frame used.
E. Power steering is allowed.
F. No rack and pinion steering. Stock OEM steering gear box must be used. May not be moved.
G. Idler arms must remain in stock location.

A. No traction control of any type!
B. Upper control arm brackets may not be moved. If damaged, must be put back in stock. Cannot move lower A-frames.
C. Must use stock upper and lower control arms and brackets for frame used.
D. Upper and lower control arm bushings may be after market.
E. Sway bars (may be removed) and brackets must remain stock. Bushings may be after market.
F. Racing springs are allowed. Steel only. No coil-overs.
G. Weight jacks ok.
H. Spindles and rotors must remain stock for frame used. Ball joints must remain stock appearing (may be welded in). No grinding or lightened parts. Bolt on spindle savers are legal.
I. No welding on spindles. Reaming spindles for balljoints okay.
J. No drilling cooling holes in rotor. 5/8″ studs are allowed in any bolt pattern.
K. All four rear trailing arms must retain stock arms for frame used. Must remain stock in length. Must not compress or lengthen. Arms may be boxed or strengthened. After market bushings may be used. No spherical or ball bearing or Timken bearings anywhere on cars suspension. Upper arms can be drilled for pinion angle.
L. No suspension parts may be altered or lightened.
M. No aluminum parts allowed, other than bushings.
N. Each trailing arm must have bushings installed and in good working order.
O. Lower A-frame mounts may be notched for clearance.
P. Spindles, brakes, and A-frames must be stock on front ends for year and make of frame.

A. Shocks must be steel non adjustable, unaltered shocks only.
B. One shock per wheel. May use spacers when mounting shocks.
C. Air shocks not allowed. No adjustable shocks.

A. Front frame horns must remain stock.
B. Rear of frame behind rear tires, no further forward than one inch behind factory seam, m ay be replaced in OEM location with two inch by three inch steel tubing with 0.095 inch wall thickness. Factory seam must remain visible. Unibody must tie rear frame to front frame. Frame may be “X” braced.
C. Front frame may be cut for radiator clearance.
D. Frame must match motor and body.
E. You cannot cut holes in frame to lighten it.
F. Frame cannot be widened, narrowed, shortened, or lengthened.
G. Cross member mounts on frame for transmission may be removed, but cannot be farther forward than welds on frame. X-bracing allowed.
H. If weights are used for ballast, weights most be painted white and number of car must be on weight. No mercury ballast or any similar type of ballast may be used. All weight must be securely fastened. Loss of weight will be cause of disqualification.

A. Main roll cage must consist of continuous hoops not less than 1½” x .095″ round tubing. All welds must be complete — no brazing or soldering. No part of main cage may extend forward past rear motor plate. Offset cages OK.
B. Main roll bar and halo must be a minimum of 1″ above the driver’s helmet.
C. A minimum of three (3) driver’s door bars, and two (2) passenger side door bars is required.
D. Four (4) bars, two per side, may extend from the main roll cage to the points on the main frame in front of the upper control arms. These bars may have two additional braces per side to the main frame.
E. Six (6) bars may extend from the main cage to the rear, X-bracing is allowed.
F. Door plates will be mandatory. At least 4″ x 12″.
G. Cages must be steel or chrome-molly.
H. These are guidelines for your cage. Build them safe.

One single nerf bar between the front and rear wheels, on each side of the car is allowed. Maximum size = 1½” x .095″. They are to be attached to the cage at the front and rear sections of the nerf bar. No center supports are allowed on the nerf bar. Nerf bars may not be outside of tires. All bumpers and nerf bars must be capped. One nerf bar on outside of quarter panel allowed.

Minimum of three (3) windshield bars 5/16″ in diameter is required. Must be mounted in front of driver.

A. Hoosier”500″or G60’s, American Racer G60’s or DOT Street tires (available to the general public at normal retail outlets and must be warranted by the manufacturer).
B. Grooving is okay. No Siping is not allowed (this means by razor blade or anything similar).
C. Only 8″ tires allowed. No recaps allowed.

A. Only steel 15″ x 8″ or steel 14″ x 8″wheels are allowed. RR beadlock is allowed.
B. No wheel spacers allowed with stock studs. Any offset wheel allowed. 5/8″ studs are allowed. Wheel spacers may be aluminum.
C. One-inch diameter lug nuts are required.
D. Wheel adapters will be treated as spacers and may be aluminum. 1½” inch maximum on spacers.

Oil and transmission fluid coolers are not allowed in driver’s compartment.

Aluminum racing seats with right side rib protection is required. A seat that provides both left and right side rib protection is recommended. Seat must be securely mounted. The racing seat must be bolted to a reinforced cross member and bracket(s). This cross member must be welded to the roll cage, not just the floorboard. The back of the seat must be supported and bolted to a flange that is connected to the cage.

Racing type 5 point settles are mandatory. Must be approved 3″ wide shoulder straps, lap belts and a minimum of one 2″ sub strap. All belt systems must be securely attached to the roll cage, or seat cross member and not to the floorboard. Seat belts must be in good condition.

Window nets are mandatory. It may be mesh or web style. Sprint car cage net is allowed. A quick release window net system must be used.

Must be an approved racing helmet in good condition. At track discretion.

Driver suit (fire suit) mandatory, may be one (1) or two (2) piece, must be complete and be of fire resistant material and in good safe condition. Fire resistant driving gloves recommended. Shoes optional.
It is at the discretion of Thunderbird Speedway to change any rules pertaining to safety at any time.

A. Engine protest must be presented in writing prior to the start of the “A” Main. Completed protest form must accompanied a $300 cash tear-down fee.
B. Tear-down fee of $300 will require the removal of one (1) cylinder head and related components to allow measurement of bore and stroke and to see piston dome type.
C. Person protesting must take the green flag in the “A:” Main that night and be signed in to the pits that night.
D. Only registered car owner in the Street Stock registration for the current year at this track may protest.
E. Owners may protest one (1) time in a four week time span on the same car.
F. First refusal to remove head for testing results in the loss of all points and pay for that night. Second refusal results in that night’s pay and all points for the whole season being lost.
G. Track may tear-down or inspect any car, any time, for any rule violation without money or protest fees posted.
H. If the protest is considered ILLEGAL on any components listed above than the driver is disqualified for the night and does not receive points or pay for that night. If the protest is considered LEGAL then the owner making the protest loses his fees and the owner of the car that was tore-down receives the $300 protest fee.
Clarifications of these rules can be made at the race track at any time!

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