Pure Stock Rules - 2/1/07 - Download PDF or Doc

2007 Pure Stock Rules

1. BODY
A. Body and motor must be same manufacturer’s line.
B. 1964 or newer American made, intermediate sized cars. No station wagons or convertibles.
C. Group 1: Intermediate size cars with a factory wheel base of no less than 105” with a ½” tolerance, except for the selected models listed in Group 2.
Group 2:
Buick 1970-1992 Century, Skylark, LeSabre, & Regal
Chevrolet 1970-1992 Camaro, 1970-1987 Monte Carlo
Ford 1970-1992 Mustang & Thunderbird
Oldsmobile Cutlas
Plymouth 1970-1992 Rear wheel drive only
Mercury 1970-1993 Cougar
Pontiac 1970-1992 Firebird & Grand Prix
D. No front wheel drive bodies allowed.
E. Must be factory stock body with all original dimensions.
F. No lowering of body frame.
G. Body may not be offset in any way.
H. All cars must run a dash. Homemade is okay.
I. After market steel body panels that meet OEM specifications are permitted.
J. All cars must have stock bumpers and grill for make and model.
K. After market stock appearing nosepieces OK.
L. Stock body lines must be retained.
M. Fenders may be trimmed for tire clearance only. If trimmed must be done neatly and rolled under with no sharp edges.
N. Doors must be welded or bolted closed.
O. Inner hood panels may be removed. The hood must have hood pins.
P. Stock windshield or Lexan must be mounted in the stock location. Plexiglas is permitted in rear glass. Wire mesh screen may be used in the front only and supported by no less than three (3) 3/8 inch steel rods, must be in front of driver. No alterations may be made to windshield opening.
2. AERODYNAMICS
A. Rear spoiler limited to 5” in height.
B. No side supports.
3. FRAME/CHASSIS
A. Frames must be completely stock.
B. Wheel base and tread width must remain standard.
C. Stock wheelbase for make and model body with a ½” tolerance (105” minimum).
D. Maximum tread width for Group 1 cars is 66.5” and Group 2 is 64.5”.
E. Roll cage must be per LMSC requirement.
F. No link up of frame sections allowed.
G. No offset frames.
H. Upper and lower control arm bushings in front may be either rubber or solid. Rear control arm bushings must be rubber.
I. All cars must have firewalls made of steel, welded. No holes. Engine firewall must remain stock. Rear firewall must be stock or minimum 20-gauge steel required.
J. Floor pan must be stock. The area can have no holes and it must be sealed.
K. Trunk pan optional.
L. Only stock standard production type sway bars may be used. Must use stock mounting positions and mounts. No heim joints.
M. Sway bar lengths, bushings and mounts must be factory.
N. No all thread rods.
4. FUEL/FUEL CELL:
A. A NASCAR or NHRA approved fuel cell is mandatory and must be contained in a heavy steel box to prevent puncture. Fuel cell may be offset.
B. NBS racing fuel only. No additives permitted. NBS has the right to withdraw the gas and refill with track gas.
5. TRANSMISSION/REAR-END:
A. Automatic transmissions or Saginaw 3 speed straight drive transmission ok. If automatic transmission is used, must have safety blanket or scatter shield.
B. Must have a Lakewood 360 degree drag racing style blow proof bell housing.
C. Must retain stock fly wheel, must weigh 20 lbs.
D. All forward and reverse gears must work.
E. Shift kit permitted.
F. No small converters.
G. No couplers or small clutches. Clutch must be stock 10 ½” .
H. Standard/Manual transmission cars must have inspection hole in bottom of blow proof bell housing. Minimum size of hole to be 1 ½”. NBS Official must be able to see clutch assembly through the location of this hole. Clutch fork hole will not be permitted for this task.
I. Drive shaft must be standard steel shaft painted white.
J. Two 360 degree ¼” X 1” loops must be installed 6 to 12 inches from both ends of the shaft.
K. Rear axle must be stock type for year being used. Absolutely NO shortening of axle housing. Ten or twelve (10 or 12) bolts rear may be used.
L. Rear axle must mount in stock location using stock brackets and arms for car.
M. Leaf or coil springs allowed. Leaf springs must fit stock location.
6. BRAKES/SUSPENSION:
A. Brakes must be original equipment for car makes and model used. No crossbreeding of parts. No adjusting devices allowed.
B. All front springs must remain in stock location in unaltered mounts. Solid spring spacers in front may be on top or bottom. Rear spring spacers only in bottom. Top of rear spring must be in stock mount. No other adjustments of any kind are allowed.
C. No screw jacks allowed.
D. Heavy-duty springs may be used if dimension and diameter are the same as stock part. It is illegal to make any adjustments to springs in rear of car.
E. Stock type shocks only. One shock per wheel. The must be in stock mounts, at original mounting angles.
F. No suspension adjusting devices allowed in driver’s compartment.
G. A-Frame must be stock and mounted in the stock location. Heavy-duty ball joints allowed. Frames must no be cut and re-welded to change length or height. May weld threaded sleeve in lower A frame to accept K727 ball joint.
H. Adjustable spacers not allowed.
I. Nonadjustable pan hard bar permitted with stock bushings.
J. No lift or J bars allowed.

7. ENGINE SPECIFICATIONS:
A. Engine and transmission must match body manufacturer.
B. Only standard production V-8 engines will be permitted. Maximum 368 cubic inches.
C. The engine must be completely stock from top to bottom.
D. No crossbreeding of engine parts.
E. No grinding or polishing of any internal parts. If casting marks are gone it’s ILLEGAL.
F. Stock stroke must be retained with a +/- ten thousands (0.010) tolerance; measuring at visible center of piston. Final value to be determined on average of 4 cylinders on same bank.
G. No hi-performance or after market parts allowed excepted where noted herein.
H. May run racing oil pan; no windage trays.
I. Camshaft and Lifters
1. Any hydraulic cam and lifters permitted.
2. No mushroom lifters.
3. No solid lifters.
4. If lifter collapses at the touch of a fingertip, you will be disqualified.
5. No collapsed lifters.
6. NO roller cams allowed.
A. Heads ***ALL PART & CASTING NUMBERS MUST BE VISIBLE***
1. Only two-barrel Venture carburetor intake and heads will be allowed.
2. Must be factory produced two-barrel engines only.
3. Angle milling allowed, no small chambered heads, including 305 cubic inch heads.
4. Valve size must be stock sized from manufacturer of engine being used.
5. The following heads are NOT permitted: 291, 041, 370, 461, 462 and angle plug heads.
6. No 202 valves.
7. No Vortec
8. No TBI heads
9. 194 Valves ONLY
10. After market valve springs OK.
A. Rods/Crank:
1. Connecting rods must remain press fit.
2. No grinding or polishing of any internal parts.
A. Pistons
1. No piston rod combination changes.
2. Pistons must be OEM replacement only.
3. No forged or flat top pistons allowed.
4. Must have original valve relief. No alterations permitted.
5. An overbore of 0.60” will be allowed. Pistons must have deck clearance of .010” (this means pistons down inside of deck 0.10”). Head gasket removed.
A. Carburetor
1. All cars must run 2-Barrel carburetor. Must be kept in same manufacturer’s line as motor used. Must be mass production two-barrel carburetors only.
2. Choke assembly can be removed.
3. Holly jets permitted.
4. Horn on top of carburetor must be retained.

5. Venturi are of throttle body of carburetor can measure no larger than the following:
Manufacturer Top Bottom
GM/Delco/Roch 1.374” 1.680”
Motorcraft/Autolight 1.330” 1.650”
Chrysler/Holly 1.325” 1.650”
***NBS has the right to refuse any carburetor***
These are the maximum dimensions allowed. Casting variance of .005 over acceptable. Venturi area cannot be enlarged in any manner. If it has been ground on it is illegal!
6. Top of carburetor cannot be ground down.
7. No carburetor spacers allowed.
8. One carburetor gasket between carburetor and intake manifold. Maximum .125 inches thick.
9. Must maintain visible carburetor number. NO NUMBER – IT’S ILLEGAL.
10. Original factory cast iron 2-barrel intake manifold required.
11. Matched porting is not permitted.
12. Removal of material inside runners is not permitted.
13. No acid dipping
14. No grinding, cutting or machining allowed.
15. Venturi cluster of carburetor cannot be altered. If any material is removed, it is illegal.
A. Fuel Pumps
1. Stock fuel pumps only.
B. Radiator
1. Aluminum radiator permitted.
2. Radiator must be in front of motor.
3. Aluminum pulleys OK.
4. Plastic type RV fans are permitted.
5. Steel stock fans are permitted.
6. Flat fans and fiberglass fans are not permitted.
A. Battery/Ignition
1. Battery may be relocated. It must be in a marine box and securely mounted.
2. Stock electronic ignitions are permitted.
3. Only a stock single point distributor.
4. Distributor cap must be removable.
5. Stock coils only.
6. No MSD components.
7. Welding permitted on distributor shafts to lock advance.
A. Mufflers/Headers
1. MUFFLERS ARE REQUIRED. NO EXCEPTIONS.
2. Schoenfeld Muffler Part #IMCA 609.
3. Mufflers must be installed so that part number is visible.
4. Exhaust pipes must exit at the rear of the doors in front of the rear tires.
5. Dual exhaust OK.
6. Headers are permitted. Frame can not be modified in any way to accept headers.
7. ENGINE LOCATION:
A. Engine must remain in stock location.

8. TIRES:
A. Hoosier tires required.
B. Tires must be purchased from David Ruley and must be branded by him. David can be reached 9-5 Monday – Friday at 540-463-3495.
C. No soaking permitted.
9. WHEELS:
A. Maximum 8 inches (8”) wide steel only.
B. Standard weight. No lightweight wheels allowed.
C. All wheels must be same size and must retain same offset.
D. Larger and longer wheel studs may be installed.
E. Spindles and hubs must be stock appearing with no offset. No drop spindles allowed.
F. Wheel spacers must be the same width from side to side.
10. DRIVER’S EQUIPMENT:
A. Racing seat with headrest required. No fiberglass seats.
B. Crash helmet required. Must be Snell 2000 or later approved.
C. Three inch seat belt, shoulder harness and crotch strap required.
D. Drivers must wear fireproof jacket. Fireproof pants, shoes and gloves are strongly recommended.
E. Driver side window net required. Must release from the top.
F. All cars will carry a 2 ½ lb. fire extinguisher.
G. No in car radios permitted.
H. No mirrors of any kind allowed.
11. WEIGHT:
A. Base weight with driver included is 3475 lbs.
B. Each car must display its NBS required weight in the top left corner of the windshield, or above top left corner.
C. NBS reserves the right to adjust weight up or down to equalize competition.
D. All added weights must be bolted to the frame, painted white and have the car number on each weight.
E. NBS reserves the right to add weight to any car winning more than three races.
12. PULL CHAINS
A. Must have front and rear pull chains that are attached to frame. Cable may not be used.
B. Failure to have both will result in purse being held until in compliance.
13. MISCELLANEOUS:
A. Steering wheel may be stock or quick release. Steering wheel center post must be padded.

NBS has an obligation to all competitors to enforce the rules. Every effort is made to carry out this obligation fairly. If you have a question about the rules as they apply to your car or conduct you should contact us in advance - that is prior to the time a problem arises.
In addition, drivers and car owners are responsible for their conduct and that of crew members as well as fans identified with the team. This is a big part of our success and very important to the operation of NBS. I expect each race team to help me with conduct issues. If you do not feel comfortable with these rules you should plan to race elsewhere.

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