1. No high performance parts allowed except as stated.
2. Wheel base 108.
3. Stock suspension - Aftermarket “A” Frame on top side
only allowed, . Lower “A” Frame must be stock for the car
that it is on.oem spindles only..
Leaf spring cars - shackles only, blocks allowed.
4. Engine - #1 plug even with ball joint max setback.
A. Stock bore - +.060 maximum.
B. Stroke - Stock for CID of engine. Crankshaft
may be aftermarket, must be stock appearing, and weigh no
less than 48lbs.
C. Rods - Must be stock length for CID of engine.
Pistons.Flat top no gas ported.No less than .062 ring
landings.The weight for rod ,piston ,ring, pin and bearings
must not be less1300 grams.
E. Camshaft - 480 lift Hydraulic or
tappet cam only. Roller rockers are OK.
F. Carburetor - Gas only. 750 Holley Max. 200 lb.
weight break. 600 Holley single line stock part # 080457.
G. Intake - Any aluminum. Max 1” adapter or spacer
plate. No porting or polishing.
H. Compression - 180 # maximum. Will be checked
with all plugs removed and throttle wide open until needle
I. Heads - Stock heads and S/R heads. Must be
stock diameter valves for CID of engine. Small Block Chevy
1.940 intake, 1.500 exhausts. Small block Ford 1.940 intake,
1.600 exhaust. May be aftermarket valves:solid steel only .
Valve springs must be stock diameter or bee hive as in ne
smith.No porting, polishing, grinding, etc. May have pinned
or screw in studs and guide plates. Three angle valve job
permitted. 170 cc. Runners max and combustion chamber must
be equal to factory
J. Ignition - MSD boxes allowed. Distributor type
or CD(Capacitive Discharge) Ignition systems only.
K. Rings, Rod & Main Bearings, Oil pumps, Cam and
Lifters, valves, valve springs, gaskets, plugs, plug wires,
push rods, bolts, nuts, etc. may be aftermarket.
L. May run aftermarket oil pans.
5. Rear End - Locked rear ends only.
Any factory type rear end. Must be mounted with
stock replacement brackets for the car that it is under
Southwest Speedway or equal. May be floater axle. May use
rear disc, calipers and hubs, must be same as factory.
(Example: front GM can be used on rear.) REAREND
must be in factory stock position, . Mounting points shall
be the same as the factory for the type of car that the rear
end is being used under. Upper and lower control arms
6. Transmission - straight shift legal. Must have
all gears and be produced by manufacturer of car. Automatics
must have working torque converter.
Functional torque converter.
7. Clutch, pressure plate, and flywheel must be
steel factory type. Minimum weight of 34lbs with no
tolerance. No modifications.
May be aftermarket. 10 ½” minimum diameter clutch.
8. Shocks Re buildable
legal. catalog price not to exceed
BUY PRICE ON SHOCKS
9. Safety Hub Right front
10. Wheels - 10in steel wheel max. Bead Lock allowed on
right rear and right front.
11. Tires . 275 x 60 maximum. Street tire, option
The add 50lb rule for running the H500 & American Racer 500
rule has been deleted
12. Bodies - Must be full bodied cars or trucks. Top,
hood, and deck lid must be original or aftermarket and must
be stock appearing.
A. Quarter panels, doors, and fender may be made
of aluminum but must be made in separate pieces and be stock
B. Tubing may be used to tie sub frame together at
factory location, parallel only.
C. 8 in. rear spoilers and side spoilers .
13. Weight - 362 and under is 3200 lbs. Greater than
362 CID is 3500 lbs.
14. Fuel tanks - a mandatory firewall between driver
and fuel tank.
15. Headers - legal.
16. Frame section in front of A Frame mount and behind
rear suspension mounts may be replaced with tubing due to
rust or excessive damage.
17. All glass and flammable parts must be removed.
18. Roll bars - All cars must have a 4 point roll cage.
4 bars on driver’s side, 2 in passenger side (1 ½” minimum
OD black pipe.)
19. 1” diameter lug nuts minimum. Must have 5 lug studs
and lug nuts per wheel
20.ANY TIME IN DOUBT ALWAYS ASK.
SOME TYPE MUFFLER IS REQUIRED,
Winterfest Modified Street Motor
Weight 3250lbs 4412 2 barrel with choke
pass no go .no modifications production straight plug head
vortech part#12407 or engine quest part #350 replacement
Valve size 2.02 intake,1.6 exhaust. Any
intake, No porting and polishing, no knife edging crank or
lighting 43lb max.
No porting and polishing heads,flat top
Transmission option: add 125lb
other than 34lb.clutch and flywheel or run 4412 2
barrel with choke horn, must pass no go . no modifications
602 crate motor 3200lb
any transmission or clutch