Pro 4 Mods

2019 Rules


a.      Fabricated Chassis only

b.      Minimum 1 ½” Diameter 095 wall tubing

c.      Must be 4-post cage with 3 U-shaped door bars on driver side w/ door plates of 1/8” steel mandatory

d.      Front and rear hoops required – Under slung chassis ok

e.      Rear Bumpers must extend past tips of spoiler, in order to be pushed from race track by tow truck

f.        Must have access through rear deck for lifting points on frame, if bumpers not strong enough to lift car

g.       Double front bumper, upper must be parallel with lower with no lean back


a.       2000cc or less, must weigh 1800 lbs or more

b.      2300cc must weigh minimum of 1900 lbs.  Every cc above 2300 add 1 lb./cc

Ie. Example:  2344cc must weigh 1944 lbs , 2500cc must weigh 2100 lbs

            c.   Left side weight must not exceed 56% of cars total weight.  No exceptions

            d.   All weight added to car in the form of lead blocks must be painted white with car # affixed, and be securely mounted to or within frame rails, with ½” bolts or larger,  If weight is found on the track there will be a $500.00 fine.

              e.   Cars may be scaled at anytime

              f.   Weight infractions must be addressed prior to entering race track, at tech’s discretion

       3.   BODIES (must resemble a full size modified)

         a.     3’ minimum ride height at lowest point including body and cross member

b.      3-3/8 minimum vertical bars in windshield area.

c.       Full windshield OK, but NOT recommended.

d.      Transponder location must be mounted 85” from front bumper, +/-1”

e.      Must have hoop protecting fuel cell

f.        All dimensions must be within tolerance.  No exceptions !

Refer to Dimensions template Page #7 for all measurements

MAX                                           MIN

A.       102”                                     94”

B.        64” Maximum track width – center to center

C.        3” Minimum ground clearance (ride height) at the lowest point including body

D.        18”                                      12”

E.         36”                                       30”


G.                                                 6” Full rear panel attached solid 90 degrees from deck. NO AIR SPACE. NO INSET PANELS

H.        20”                                       15”

I.          61”                                       53”

J.          50”                                      42”

K.        56”                                       41”

L.         42”                                      30”

M.      74”                                      68”

N.       30”                                      24”

O.      112”                                    96”

P.       46”                                       40”

Q.      34”                                       27”

4” interior rake from fire wall to spoiler, interior deck must attach to top of doors and rear quarters and be flat from left to right

2” Max roof rake in 24” measured at center of roof

  1. MIRRORS: 

a.       No mirrors allowed


a.        Any 4-cylinder, single overhead cam engine

1.        2550 cc MAX (long rods OK.  NO Strokers)

2.        2 valves per cylinder engines

3.        Stock Steel or Stock Aluminum Cylinder Heads allowed 

4.        No roller cams and .500 lift max, Measured at the Valve.

b.       12” maximum engine set back +/- ½ “ measured from center of lower ball joint to #1 spark plug

c.       No dry sump oil systems

d.      Intake Manifold Match porting up to 1” from head flange will be allowed.  No other alterations will be permitted.  No Acid etching

e.      Any stock intake

f.        No turbo chargers or nitrous allowed.


a.      Must exit car away from the driver and 6” behind driver seat

b.      Must meet 90 dBA at 100 feet or track specifications


a.      Must be carbureted -- no fuel injections

b.      Holly 2-BBL 500 or 350 c.f.m. only or comparable,  “GO no GO” gauge will be used.  No removable venture.  Two return springs mandatory must be mounted separately.

c.       No aerosol type carburetors

d.      No billet metering blocks allowed

e.      1” Carburetor adapter MAX. Only one .065 gasket per side of adapter (open adapter only).

f.        Battery must be securely mounted outside of the driver compartment.  Must have Master kill switch within reach of the driver

g.       Ignition point or MSD allowed (NO CRANK TRIGGER IGNITION)


a.        Radiator must be mounted in front of the engine

b.       1 qt. overflow required

c.       Water wetter - ok and recommended


a.       Any stock production transmission.  NO RACING TRANSMISSION.  All gears must work

b.      Steel drivelines must be painted white and have at least 1 hoop of steel strap.  1/8”x2” min. 6” from front U-joint max

c.       Any steel stock operating clutch or fly wheel is permitted.  No Couplers or Buttons

d.      Aluminum fly wheels allowed but must have steel inserts

e.      Scatter Shields mandatory


g.       Gear rule to be determined if needed


a.     Shocks – NO CANISTER TYPES. (NO adjustable shocks allowed) (NO re-buildable or changeable valve shocks allowed) (NO Exceptions)

b.      NO spring rubbers

c.       NO BUMP STOPS

d.      NO spline bars allowed

e.      Stock or Slapper style sway bars permitted

f.        Steering quickener's allowed

g.       Coil over kits allowed

h.      Aftermarket Uppers allowed

i.       Stock Pinto Spindles (must have FORD or I.M.C.A. stamp), No McPherson Strut type

j.        Weight jacks allowed on front and rear

k.       Fabricated lowers allowed


a.      Any Make

b.      7”, 8”, 9” Stock/Floaters allowed, NO Quick change allowed

c.       Mini/Full Spools allowed

d.      Must run  locked rear gears

e.      Welding of gears is permitted

f.        Detroit lockers or ratcheting type rear ends NOT permitted

g.       No spring loaded or biscuit style trailing arms

h.      3 or 4 link or leaf spring rear suspension allowed only

i.        NO birdcages allowed

j.        1 shock and 1 spring per wheel allowed

k.       Coil over kits allowed

l.         Shocks – NO CANISTER TYPES. (NO adjustable shocks allowed) (NO re-buildable or changeable valve shocks allowed) (NO Exceptions)


a.        All four wheels must have functioning brakes

b.      Any stock or aftermarket Rack and Pinion OK


a.       Any steel racing wheel – 13X8” MAX any offset allowed

b.      Wheel spacers allowed for alignment purposes only


d.      Track Tire Only


a.       Fuel cell must be of 20 gauge steel with Polyethylene inner shell.  Must have fuel cell guard below cell.

b.      Must run two 1/8”X2” steel flat straps around the fuel cell or 1” square tube

c.       Must have vent and a tip over valve.

d.      Murphy switch required with electronic fuel pump, must be functional

e.      Max 110 octane fuel - NO ADDITIVES – RACE GAS ONLY

f.        Must run ground strap to fuel filler collar

g.       Must run 1/8” plate behind fuel cell the width of the cell for protection

h.      Fuel cell is min. 8” from ground

(Stock means unchanged or unaltered an anyway)

The first time any part of the car is found to be illegal it will result in a fine of $250.00 and lose of points and money for that race.

The second time any part of the car is found to be illegal it will result in a fine of $500.00 and loss of points and money for that race.

The third time any part of the car is found to be illegal it will result in a fine of $500.00, loss of points and money for that race and one week suspension. 



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