2008 Southern Invitational
6,500 lb Limited Light Super Stock Rules
1.) Drawbar hook point is to be a minimum of 18 inches behind
center of rear axle and a maximum of 20 inches high. Drawbar
is to be rigid in all directions. Hitching eye is to be a minimum
of 3 inches in diameter and a minimum of ¾ inches in
thickness. Drawbar must have on inch of steel from outside of
hole to outside of drawbar.
2.) Area 6 inches wide and 12 inches immediately above the
drawbar must be free of all obstruction.
3.) S.F.I. approved clutch, flywheel, and pressure plate are
4.) Safety tie bars mounted to the rear axle housing with at
least 2 axle housing bolts and extending forward of flywheel
area and fastened to side of block or main frame with at least
two 5/8 inch bolts; OR a one piece frame extending from front
of tractor to rear axle housing mounting bolts. Note
tie bars or frame must be of sufficient strength to support
weight of tractor with the bolts used to split the tractor removed.
5.) Flywheel guards must be used. A 20-ply ballistic nylon
or 20-ply Kevlar 17 inch wide and long enough to wrap around
the bellhousing with at least 6 inches of overlap secured with
six 2 inch wide nylon web straps with steel D-ring and sewn
the length of the blanket and secured front and rear with straps.
6.) The chassis shall consist of the following: a. The stock
engine block or its replacement as listed of the manufacturer
for that make. Example: IH tractor must use IH engine. b. The
stock transmission housing or manufacturers replacement c. The
final drive housing or manufacturers replacement. The original
equipment manufacturer engine block or manufacturers replacement
cannot be modified externally in any way except normal repairs.
No aluminum replacements of engine parts, clutch housing, transmission
case, rear end housing or rear axle housing.
7.) Tractor wheelbase will be a maximum of 114 inches from
the center of the rear axle to the center of the front axle.
8.) All tractors must have wide front end.
9.) Tractor length of 13 feet maximum from center of rear wheels
to the farthest point forward including front weights.
10.) Tire size limit is 30.5x32. No chains, duals, or 4 wheel
drives allowed. Double cut tires are allowed with biased type
tires only. Cut and ½ are allowed in biased or radial
11.) Side shields must be equipped and should be of 60 thousands
steel or aluminum which is to be securely fastened to the tractor.
They should cover from top of the frame to the hoods and as
long as the engine.
12.) It is recommended that a quick release fastener be used
(winged nut type or cotter pint type hood pins). Reason: ease
of access in case of emergency.
13.) All tractors must have fenders or a shield between the
driver and tires to consist of a solid barrier between driver
and any part of rear tires sufficient to support weight of driver.
14.) Tractors must have a strong and rigid seat with seat belts
anchored to something other than the seat itself.
15.) Stabilizer bars are required. The drawbar assembly must
in no way be attached to the stabilizer bars. Stabilizer bars
will extend a minimum of 32 inches behind a line drawn from
the center of the wheel to the ground. The stabilizer pad must
not be more than 10 inches off the ground. The stabilizer pad
must be a minimum of 8 inches square. A minimum of 20 inches
will be allowed from the outside of one pad to the other. Stabilizer
bars are not to be mounted in any way to the drawbar. Note
The stabilizer bar system must be able to support the weight
of the tractor in the heaviest class pulled. Jacking up the
pads so the tractor is completely off the ground will be a good
16.) A 2.5 pound fire extinguisher, preferably Halon, must
be convenient to operator.
17.) Fire helmet and full length pants are mandatory.
18.) The use of a protective roll cage or R.O.P.S. device is
19.) Engine must be manufacturer designed block for that make
with factory appearing head for that tractor at the time of
manufacture. No aluminum heads allowed.
20.) Diesel cubic inch limit is 470 with one turbo limited
to 3" on intake side, no slots or enhancement ring. Diesel
tractors under 360 cubic inches may run two 3"x4"
turbos. Alcohol cubic inch limit is 370 with one turbo limited
to 3" on intake side, no slots or enhancement ring. Naturally
aspirated gas/diesel/propane engines may be up to 850 cubic
21.) If turbo has MAF enhancement, or "slots", these
must be welded permanently for competition.
22.) Tractor must have 200 lbs. of moveable suitcase weights.
23.) P-pumps or any pump smaller allowed. No French pumps allowed.
24.) Must use stock fuel for make and model of tractor. Gasoline,
diesel, and propane are considered stock primary fuels. Ether,
oxygen, alcohol, nitrous oxide, nitro methane are all illegal
fuels for primary or secondary fuels.
25.) Water injection systems shall use water or a mixture of
water and lubricant only.
26.) No pressurized tanks except propane, when used as a primary
27.) Turbochargers only. No roots type blowers, belt driven
blowers, or superchargers permitted.
28.) No air bleeds or secondary air allowed on intake (compressor
29.) Turbocharger must be under hood or shrouded end to end
and 360 degrees around with .60 steel or heavier. It must be
shrouded if under a fiberglass hood.
30.) Exhaust pipes must have two 3/8 inch grade 5 bolts set
with 1 inch and 90 degrees to each other in the vertical part
of the exhaust or pipe.
31.) Tractors must have automatic ignition kill switch and
air shutoff in working order at all times. Tractor officials
or tech inspectors have the option of checking kill switches
as often as they deem necessary. On a spark engine the kill
switch must break or ground ignition and shut off electric pumps.
On a diesel, the air shutoff must have a spring loaded closing
mechanism. To be deemed acceptable it must prevent building
boost. It is recommended that a gasket seal be used. A mechanical
shut off, controlled from the seat, must be placed in the fuel
line before the injection pump.
32.) The kill switch hook up will be located in the rear center
of the tractor. Maximum 6 inches off center in any direction
approximately 48 inches above its point of hook. A 2 inch ring
should be made available to the sled.
33.) All tractors must have a dead man throttle which automatically
retards to idle position when released by the operator.
34.) Tractors must have a bulkhead shield between driver and
engine from top of hood to op of torque tube or transmission
housing or clutch housing from side shield to side shield. This
also serves as a flash fire shield.
35.) A safety light system is required on all pulling vehicles.
A white light, automotive quality, minimum 2 inches in diameter,
must be mounted directly above or below the safety kill switch
at the rear of the vehicle. The light must be activated by a
shift lever so that when placed in reverse will activate the
36.) Tractors must have an electric operated cooling fan. Stock
steel bladed fans that are driven by a belt are not allowed.
37.) A .0060ths thick steel shield must run between the frames
and under the harmonic balancer to prevent loss of harmonic
balancer from the tractor.
38.) Modified intake and exhaust headers are permitted.