Pure Stock
HUNTSVILLE SPEEDWAY PURE STOCK RULES 2025
RULE BOOK DISCLAIMER
The rules and/or regulations set forth herein are designed to provide for the orderly conduct of racing events and to establish minimum acceptable requirements for such events. These rules shall govern the condition of all events, and by participating in these events, all participants are deemed to have complied with these rules. NO EXPRESSED OR IMPLIED WARRANTY OF SAFETY SHALL RESULT FROM PUBLICATIONS OF OR COMPLIANCE WITH THESE RULES AND OR REGULATIONS. They are intended as a guide for the conduct of the sport and are in no way a guarantee against injury or death to a participant, spectator or official.
The race director shall be empowered to permit reasonable and appropriate deviation from any of the specifications herein or impose any further restrictions that in his/her opinion do not alter the minimum acceptable requirements. NO EXPRESSED OR IMPLIED WARRANTY OF SAFETY SHALL RESULT FROM SUCH ALTERATION OF SPECIFICATIONS. Any interpretation or deviation of these rules is left to discretion of the officials. Their decision is final.
The Management of Huntsville Speedway
Due to the many types of cars that can be built under the Pure Stock rules, it is impossible for these rules to cover every situation that might occur. Officials are given discretion, following the intent of the rules and to rule on any matter not covered specifically in the rulebook.
Warning! If you attempt to abuse the rules set forth by Huntsville Speedway for the 2025 Pure Stock Division, we will have no choice but to refuse your request for participating. Just because the rules don’t say you can’t, does not mean that you can!
Safety
Refer to Huntsville Speedway’s General Rules for a full list of rules regarding driver, pit and car safety.
Competition Rules
1. Unless specifically mentioned in the following rules, the Super Stock division is designed to be an affordable and simple form of racing. Please keep it that way. If it is not stock, or otherwise addressed in the rules, it is not legal!!
2. Recommended 2” view hole in oil pan for inspection of crank & rods.
3. Racing radios and neck restraints recommended.
4. No traction control devices of any kind allowed.
Before Start of Race
1. There will be a draw or qualifying to determine starting order.
2. All starts will be double file, cone rule will apply on restarts. The winner of the previous race will start in the rear the next race he/she competes, regardless of the draw or qualifying order.
Competing Models
1. Rear wheel drive only. Must be stock unaltered OEM GM chassis. Ford driver must see HS official for approval.
2. All stock equipment only for that year, make and model car unless noted in rules.
3. May run 2 or 4 door car. Cars must be a minimum 108” wheelbase. Sub-framed cars allowed, but must have frame connectors. No Camaro, Firebirds, Corvette bodies/chassis or T-top bodies permitted. No 1970-1972 Monte Carlos permitted without prior approval by HS Officials. Preapproved real leaf spring cars allowed with a 150 lbs penalty placed in center of right front floorboard.
Weight
Option 1: Minimum weight of 3400 pounds for box stock 500CFM Part #4412 or a unmodified Stock OEM four barrel quadrajet at qualifying and after the race.
Option 2: Miniumum weight of 3100 pounds for box stock 350CFM Part #7448 at qualifying and after the race.
2. No fuel burn off allowance.
3. Maximum 55% left side weight
4. Any car deemed with an unfair advantage will have to add weight at the discretion of the HS officials.
5. All ballast weight must be mounted securely and painted white with your car number on each of weights.
6. Weight boxes or ballast weight cannot be mounted any lower or to the lowest part of frame rails facing the ground anywhere, even in the trunk. No weights shall be hung or mounted directly in front of, behind or under the gas tank.
7. Management reserves the right to alter, change or adjust weight limits to all conforming and non-conforming race cars without consulting any competing driver.
8. All weight penalties will be placed center of right front floorboard. This excludes choice of carburetor weight.
Bodies
1. May remove both front inner fenders. Rear inner fender wells must remain full and intact. May cut out front fender 3” around tires. Radiator must remain in stock location. Doors, door jambs, bottom side of hood and trunk may be gutted. All fabricated body parts must be minimum of 26 gauge steel and be stock appearing. i.e. No straight or flat sides
2. Car must not have any sharp or pointed edges that could harm or injure the driver, tech official or safety crew.
3. Must remove interior, headlights, taillights & all side glass, must leave interior open.
4. Must have 1/8” Lexan/Polycarbonate full windshield. No Plexiglas- No Exceptions. Must allow 5” at top of windshield for division sponsor sticker.
5. All doors must be welded or bolted shut.
6. Side skirts allowed, but no lower than 4” from the ground.
7. 6” x 60” maximum spoiler dimensions. No side foils, fins, splitters, chin spoilers, or ledges allowed anywhere.
8. Numbers must be of distinguishable color and must be at least 20” high. Numbers must appear on both sides and on the roof of the car. Indistinguishable numbers may result in scoring errors.
9. Must run full stock appearing body. Floors, firewall and roof must be fully intact, except for roof center support.
10. No sectioning, chopping, channeling, or cutting of any kind to exterior body except for tire clearance.
11. All holes in front and rear firewall and floorboard must be covered with 16-ga steel.
12. Minimum of 4 quick release pins in hood and 4 quick release pins in the trunk.
13. Complete body must be minimum 26 gauge steel with the exception of the front nose, tail covers, hood and trunk lid. Plastic molded nose and tail piece allowed. Fiberglass hood and trunk lid allowed.
14. No carbon fiber or aluminum body parts anywhere.
Interior
1. Car must have a four point roll cage with four bars in drivers door running horizontal. Passenger door must have a minimum of an “X” bar with horizontal bar on top or identical to drivers side roll cage. All roll bar tubing must be 1 ¾” od x .095 wall.
2. Roll bar behind driver’s seat must be positioned in line with doorpost. Abuse of this rule will result in weight penalties.
3. Roll bars must be completely welded around all connecting joints. Absolutely no pipe or pipe fittings.
4. Roll bars within driver’s reach must be padded. No swimming pool noodles. SFI rated recommended.
5. 1/8” steel platting of the roll cage or 1/8” solid steel plate required inside of drivers door from A post to B post.
6. Seat and seat belts must be attached to roll cage only.
7. You will be allowed to run bay bars to support the front part of the frame and 2 bars to the rear of the frame (welded no further towards the rear than the front side of the rear spring buckets).
8. Battery must be at least 18” from fuel cell and approved by Huntsville Speedway.
Must have emergency cut-off switch within drivers reach and highly visible to safety crew. All 12 volt connections must be safely insulated.
9. Interior must remain open. Must be able to view complete floor pan or weight penalties will apply.
10. Must have a 2 pound minimum, fully operational fire extinguisher with a gauge and with a all steel quick release mounted securely in car within reach of driver while belted in car.
11. Must have quick release type window net on drivers side window. Window net must release from top of net towards front of car and highly visible to safety crew. Driver must be able to release net from inside car. Mirrors allowed inside car only.
12. Must have aluminum racing seat; belt & shoulder harness minimum 2 inches wide. Must have belts and seat secured to the roll cage. No chains ran through floorboard to secure seat.
Suspension
1. Front & rear springs must be the same diameter and height of other (front to front, rear to rear) and fit in spring pockets. Minimum 5” in diameter. Spring rubbers allowed.
2. Rear leaf springs allowed with a 150 lbs penalty to be placed in center of right front floorboard. Leaf springs must have same number of leafs on each side. Must mount in both front and rear factory mounting locations. No screw type wedge adjustments permitted. No sliders, no lowering blocks or pinion shims allowed.
3. No altering of the front lower control arms permitted. Steel, polyurethane or rubber bushings allowed on front lower control arms. Stock GM sway bars only. May have only one end adjustable at the left or right lower control arm with the opposite end fixed. Must remain in stock location and inside the stock brackets at the frame.
4. Stock OEM or all steel aftermarket front upper A-arms/control arms permitted. Maximum upper control arm bolt length is 3”.
5. Camber, caster and toe are the only adjustments that can be made to front suspension. No cutting, grinding, welding or bending allowed on spindles or steering links.
6. Adjustable steel spring cups permitted on all four corners. No wedge bolts permitted anywhere.
7. Rear upper and lower control arms must remain stock length and unaltered, including reinforcing. Pinion angle can be adjusted. Only by drilling upper control arms at rear end. Adjustment holes must be reinforced with washer and securely welded.
8. Rear control arm bushings may be replaced with hard Polyurethane or OEM rubber replacements only.
9. All steel heavy duty stock appearing OEM replacement upper and lower ball joints permitted only.
10. OEM spindles only. Must be correct for chassis being used. Spindle part numbers must be present and clear to read.
11. NO RACING OR PERFORMANCE PARTS ALLOWED UNLESS NOTED HERE IN THE RULES.
Shocks
1. Any stock appearing steel body non-rebuildable, non-adjustable replacement shock allowed. No aluminum or air shocks allowed. One shock per wheel, must be mounted in original factory mounting location. No steel bearing mounting shocks allowed. No bump stops, frame stops or suspension limiters of any kind allowed.
Post Race Shock Buy Out – $60/per shock claim rule. Buyer must buy all four shocks at time of protest. All four shocks must be delivered to tech official undamaged and fully functional. Any person that does not submit to the claim rule will be Disqualified, NO Points, NO Money. Also, they will not be allowed to bring those shocks back at any time. Huntsville Speedway also reserves the right to purchase all competing shocks in this division at any time to preserve equal and fair competition.
Rear end
1. Rear-end must remain stock for year and model of car. Rear end brackets must remain in factory location with factory welds. May have either welded, mini spool or stock/open rear end (no factory or aftermarket lockers of any kind)
2. No floating type rear end of any kind.
Brakes
1. Front brakes and rotors must be original GM or OEM stock replacement with single piston steel calipers.
2. Only one OEM stock replacement master cylinder allowed.
3. No hydraulic brake pressure adjuster or block off valve of any kind.
4. No rear disc brakes permitted. Drum brakes on rear only.
5. Brakes must work on all four wheels.
Frame
1. No altering of chassis in any way. Repaired chassis may be subject to weight penalties if repairs are done incorrectly.
2. Sub-frame cars must have frame connectors approved by Huntsville Speedway.
Fuel Cell
1. Fuel cell with roll over check valve required in trunk area in metal box and must have a firewall between fuel cell and driver. Minimal amount of cutting for fuel cell/box to fit through trunk floor pan will be allowed.
2. It is recommended that fuel cell should be located as far forward as possible, but stay behind the differential housing. Fuel cell must be between frame rails with proper ground clearance and secured with two 1/8” x 2” steel straps or four 1/8” X 1” steel straps and must be approved by HS officials. Full fuel cell cage welded to the frame is recommended.
3. Fuel cell may not be lower than 10” to the ground and must be protected by one protector bar extending the width of fuel cell with one center brace. Protector bar must be 1 ¾” X .095 and at least 1” lower than cell and is approved by an HS official.
4. No electric fuel pumps allowed. Camshaft driven fuel pumps only.
Engine
1. Chevy 350 ci only with maximum bore of 4.060”
2. Stock OEM or aftermarket crankshaft with 3.480” stoke only and weighing a minimum of 49 lbs. No knifing or polishing of rods or crankshaft. Minimum balancing of engine is allowed.
3. Stock pistons or stock replacement type pistons only. Must have four eyebrows in the top of piston with .250 to first ring land. No racing or forged pistons of any kind allowed. Floating wrist pins permitted
4. May run stock OEM or aftermarket steel rods. (No H beams) Rods must maintain stock length of 5.700”.
5. Engine block minimum deck height is 9.000
6. Any stock or aftermarket oil pan permitted.
7. May run stock or OEM replacement engine. No sodium or titanium engine parts of any kind.
8. No lowering or setback of engine from factory permitted.
9. 5800 RPM/rev limiter chip must be mounted in MSD Soft Touch Rev Control Box #8728 and fully functional at all times. Box must be mounted on right side firewall 20 inches or less from center of distributor shaft. Box will be tested at 3000 RPMs. Chip will be tested for 5800 RPMs.
Heads
1. Stock OEM heads only, 72cc minimum combustion chamber. Maximum 1.94 intake valve and 1.50 exhaust valve. Stock replacement stainless steel valves permitted.
A. Heads must be strictly stock. Heads must maintain OEM casting numbers.
B. No porting or polishing anywhere. No deburring!
C. No racing or high performance heads.
D. No cutting of heads to install larger valve springs. Maximum valve spring size is 1.255”. No more than a single valve spring with dampener and must be magnetic steel. No beehive valve springs allowed.
E. Screw in studs and guide plates permitted.
Cam Shafts
1. Any hydraulic flat tappet cam allowed, 1.5 ratio steel rocker arms only. No roller rocker arms permitted. No roller or solid lift cam shafts permitted. No mushroom lifter, anti-pump up or over-sized lifters allowed. Lifters must bleed down during tech. 15 minute allowance only.
Intake and Carburetor
Option 1.
1. Any stock OEM cast iron four barrel intake allowed with a 1” metal spacer plate. GM low profile aluminum/marine intake allowed with a 1” metal spacer plate. No porting or polishing of either intake manifold anywhere.
2. One unmodified Stock OEM four barrel quadrajet carbruator only.
Option 2.
1. Edelbrock Performer intake Part #2101 with adaptor plate plus a spacer plate together not exceeding 1” and a box stock Part #4412 Holley 500CFM, or Part #7448 350CFM two barrel only. Choke flap and horn may be removed. No porting or polishing of intake manifold anywhere.
2. Edelbrock Performer intake Part #2701 with adaptor plate plus a spacer plate together not exceeding 3/4” and a box stock Part #4412 Holley 500CFM, or Part #7448 350CFM two barrel only. Choke flap and horn may be removed. No porting or polishing of intake manifold anywhere.
In addition to options 1 and 2:
1. All carb options must be 100% box stock with no visible signs of modifications and must pass HS No-Go gauges.
2. Must have a throttle stop and two return springs.
3. Air cleaner maximum diameter of 20” and 5” in height. Must be on car while on track. Jamb nut recommended.
4. Must run Huntsville Speedway 110 octane racing fuel. (ie No E85, alcohol, or oxygenated fuels or additives of any kind)
5. No cold air boxes allowed.
6. No electric fuel pumps.
7. Maximum of all total gasket height not to exceed 1/8” between carburetor and base of intake.
Exhaust
1. No headers allowed. Stock cast iron unaltered rear dump exhaust manifolds only. Exhaust pipe must be 30 inches past bell housing with muffler.
Ignition
1. Must have stock HEI type ignition. 5800 RPM/rev limiter chip must be mounted in MSD Soft Touch Rev Control Box #8728 and fully functional at all times. Box must be mounted on right side firewall 20 inches or less from center of distributor shaft. Box will be tested at 3000 RPMs. Chip will be tested for 5800 RPMs.
Transmission
1. Only stock unmodified TH350 transmissions allowed. Must have working torque convertor. Does not have to be for make and model of car.
2. All transmissions must have 3 forward gears and a reverse gear.
3. May run solid or OEM replacement transmission mounts.
Driveshafts
1. Steel drive shafts only. Must have at least one drive shaft safety loop, minimum of 1/8” steel strap or 1” tubing looped around the driveshaft within 24” of rear ujoint.
Cooling System
1. No antifreeze permitted. $250 fine.
2. Overflow on radiator must have catch can.
3. Aluminum radiator allowed.
Tires and Wheels
1. American Racer KK704 only. Must have Huntsville Speedway stamp. (subject to change for special events)
2. Only steel 8” racing wheels allowed.
3. No wheel adaptors or spacers.
4. Must have 1” lug nuts.
5. No wheel weights allowed.
6. No beadlocks, air bleeders or pop-offs.
7. Maximum 1” offset from left to right.
8. 5/8” studs recommended.
If you have any questions about car rules, call Huntsville Speedway office.
