Class Rules

**Other Class Rules will be posted after Board Meeting February 2nd, 2019**

Click below or scroll down for rules:

Open Four Wheel Drive Trucks

Pro-Stock Four Wheel Drive Trucks

Light Limited Super Stock Tractors

Two-Wheel Drive Trucks

Two-Wheel Drive Trucks follow PPL Rule Book except any body style allowed.

Open Four Wheel Drive Trucks

Blower Trucks – Blower Overdrive Unlimited; Hitch 30% of Wheelbase; 26 Inch Height; 6200 Lbs.

Modified Trucks – Hitch 30% of Wheelbase; 26 Inch Height; 6500 Lbs.

Diesel Trucks – Refer to NTPA Rulebook on Wheelbase – Hitch – Weight

Pro-Stock Four Wheel Drive Trucks


    Pro Stock 4WD Rules-Mid-South Pullers Association

      1. Pro-Stock 4WD trucks shall follow current P.P.L Rule Book for Modified Four Wheel Drive except where superseded by rules found herein.
      2. Any truck body, any factory frame.
      3. Carburetor must have a stock 4500 base plate. No stretched carburetor. No tunnel ram or sheet metal intakes. No billet intakes or billet carburetors.
      4. Engine & Head Specifications:
        1. Maximum 485 cubic inch. Any GM style block must be 4.84 bore spacing. Any Dodge style block must be 4.8 bore spacing. Any Ford style block must be 4.9 bore spacing. No JC50, JC51, DRCE3, or aluminum blocks. Engine can be no further forward than 12 inches from front of block saver plate to center of front axle housing.
        2. GM may run any conventional port designed head. Ford may run an “A” style head. Dodge may run a B1 head.
        3. Cylinder heads must have identification logo or cast numbers to prove their original origin and how it was manufactured. GM cylinder head intake valve length can not be any longer than 6.420 in overall length maximum.
        4. Conventional port designed head is classified as a head with the port spacing that must be left to right. GM cylinder heads intake flange measurements are a maximum of 4.100 outside of port to outside of port but can be smaller. Measurement between runners is a maximum of 0.415 but can be smaller. If tech official has any discrepancies over casting or port measurements may revert to picture below:

4.100 Max  .415  Max

      1. No spread port, billet, conventional spread port heads, Pontiac, GM LS heads of any kind small block or big block are not allowed.
    1. Headers and open exhaust allowed, must exit through hood or down and back.
    2. Body Specifications:
      1. Factory wheelbase may be shortened or lengthened to maximum of 134 inches. Bedside may be altered in front of wheel wells to match wheelbase on all trucks.
      2. Rear wheel width cannot be narrower than 34 inches from inside bead to inside bead of rear wheels.
      3. OEM fiberglass components only. Front clip of truck (firewall forward only) can be fiberglass.
    3. No working hydraulic stops on front suspension during pull. Weight boxes must stay stationary before crossing the scales and cannot be moved until after the pull is over. Any air pressure adjustment requires a re-measurement of hitch height.
    4. Any street legal tire may be run measuring  up to or less than 33 inches in measured height. Terra and Cepek tires allowed along with any bar tire up to 31×15.50×15.  No recapped tires allowed. Must have size on sidewall by manufacturer.
    5. Any transmission, transfer case, front end, or rear end allowed. No planetaries.
    6. Hitch Specifications:
      1. Hooking point has to be horizontal on hitch.
      2. Drawbar will be 26 inches, 36% of wheelbase length. No drawbar greater than the angle of the sled chain (acceptable angle 0 degrees to a maximum of 33 degrees). The drawbar adjusters cannot attach to anything above centerline of the rear axle. The adjusters can only go downward.
    7. Acceptable fuels are race gas or alcohol. No oxygenated fuels, oxygen carriers, or combustion accelerators.
    8. 1% tolerance on engine measurements.
    9. Rules are locked in from 2019-2021. To unlock rules before 2021 there has to be a 70% majority vote from the class before it can be discussed.
      1. Members must make 50% of pulls to be eligible to vote on any class rules or unlocking the rules.

Light Limited Super Stock Tractors



  • Tractor weight will be 6200lbs.
  • 50lb variance will be given at the scales


  • Engine crankcase, block, and cylinder head must be of same manufacturer, or factory replacement and can be used in any agricultural transmission and rear end that used that brand of engine, or through its company mergers used that brand of engine.


CNH=                          AGCO=

Case                            Oliver

Farmall                        Moline

International                White

CaseIH                        Massey Ferguson

Ford                             AC

New Holland               Deutz

  • Must be OEM engine block, no Billet steel or aluminum blocks.
  • Engine must match brand of tractor.
  • Rear of engine must be in stock location for make and model of rear end and transmission housing, with a maximum tolerance of a 1” adapter plate.
  • A 1% tolerance will be given on cubic inch limitations to allow for normal engine wear.
  • No V-8 Engines permitted.
  • No Overhead cams allowed.
  • The largest fuel system allowed is a “P”-pump with one plunger per cylinder and one injector per cylinder.
  • No electronically controlled fuel system allowed.
  • No secondary source of fuel (liquid or gas) or oxygen enhancer allowed.
  • Water injection allowed with oil lubricant only, no additives allowed in injection water, and water will be subject to testing.
  • Computer can only be used for data acquisition, may not be able to control engine timing, or fuel delivery.
  • No traction control.
  • Exhaust must be discharged vertically; no rain caps or curved pipes at outlet allowed, and exhaust pipes must be securely fastened to tractor.
  • Exhaust pipes must have two 3/8” grade five bolts set within 1” at 90 degrees to each other at least one foot below opening in the exhaust.
  • Harmonic balancer must be shielded with at least 1/8” metal underneath the front of the block and secured to the frame with four 3/8” bolts.
  • Engines must have one 3/8” safety cable completely surrounding the block and head passing between the first and second cylinders, through the exhaust manifold port area, with a minimum of four clamps at all splices with 4-6 inches of slack.
  • Diesels must have a spring-loaded closing mechanism air shutoff. To be deemed acceptable, when activated. The shutoff mechanism must prevent boost of engine. The kill switch must be mounted securely to the back of the tractor and have a 2-inch diameter ring (minimum 1/8” thick). Operator must also be able to operate from the driver seat.
  • Alcohol engines must have a kill switch to disable the ignition.
  • Diesel fuel system must have manual three-way dump valve installed ahead of the injection pump, to be operated by the operator from the driver seat.
  • Must have “Dead Man” throttle with two return springs that automatically returns to idle when released by operator.
  • No mechanical fans allowed.
  • Flywheel will be made of steel or aluminum and be SFI approved, absolutely no cast iron allowed, and all clutch assemblies will be steel and SFI approved. No cast iron.

Diesel Engine Options

  • Maximum of 315 cubic inches for twin turbo charged diesel engines with Intercoolers. (Turbo(s) must be staged)

o   This engine combination can run a maximum of two (2) 3X4 smooth bore turbo(s). No MAF enhancement.

  • Maximum of 360 cubic inches for twin turbo charged diesel engines and no intercooler or after cooler allowed. (Turbo(s) must be staged)

o   This engine combination can run a maximum of two (2) 3X4 smooth bore turbo(s). No MAF enhancement.

  • Maximum of 410 cubic inches for single turbo charged diesel engines. Intercoolers allowed.

o   This engine combination can run a maximum of one (1) 3X4 turbo with MAF enhancement.

o   0.200 MAF enhancements

o   No forward facing MAF.

  • Maximum of 470 cubic inches for single turbo charged diesel engines. No intercoolers allowed. (The 478CI Hercules engine will be legal to run in its factory combination 0% variance on CID)

o   This engine combination can run a maximum of one (1) 3.4X4 smooth bore turbo.

o   For the 2017 season a single 3X4 turbo with MAF enhancement will be legal for the 470CI diesel engine, Max of .200 MAF with no forward facing enhancement. The 3.4X4 smooth bore turbo is on a trial basis and will be reevaluated at the end of the season. In the 2018 season this engine combination will move to only a smooth bore turbo.

Alcohol Engine Option

  • Maximum of 370 cubic inches for single turbo charged alcohol engines. No intercoolers allowed.

o   This engine combination can run a maximum of one (1) smooth bore 3X4 Turbo

Turbo Restrictions

  • All turbo compressor and exhaust wheels must protrude into the housing no less than 1/8th of an inch.
  • The compressor wheel must measure no larger then 3-inch at the face of the wheel.
  • Diesel engines that will be allowed to run a 3.4X4 smooth bore turbo, the compressor wheel must protrude into the housing 1/8th of an inch and the compressor wheel must measure no larger then 3.400” at the face of the wheel.
  • No superchargers allowed.
  • Turbocharger(s) must be under stock hood or shrouded end to end and 360 degrees around with .060” thick metal. Turbocharger(s) must also be shrouded if under a fiberglass or plastic hood.

Cylinder Heads

Cast iron OEM cylinder heads only. No billet or re-cast cylinder heads allowed.

Cylinder head must match the engine block.

Valves must maintain the factory angle, lateral movement of valves ONLY. Valves must seat in the bottom of the OEM head on all 6-cylinder engines.

Cylinder heads are limited to two (2) valves per cylinder.

One spark plug per cylinder ONLY.

Only one (1) plate will be permitted between the top of the block and the bottom of the cylinder head, with a maximum thickness of 1 1/8th inch.


  • Maximum length 13 feet measured from center of rear axle to forward most point, excluding tow hook.
  • Maximum wheelbase 114”.
  • OEM tractor rear end, transmission and axle housings only will be accepted, no component tractors allowed.
  • No type of front end suspension will be allowed, swivel axle front ends will be accepted.
  • Allow tractors with cast tub (belly)-type frame (ie., Oliver, Cockshutt, White) to remove complete frame from front of transmission housing. The Engine and clutch housing to remain in original location and mounted solid as intended by original manufacturer, with motor mounts in the front and rear of the engine. No engine cradles.
  • Once the tub is removed the rear of the engine cannot be exceed 60 inches from the center of the rear axle.
  • Tractors that have removed the tub (belly)-type frame will be required to have 100lbs of non-movable weight mounted onto the belly of the tractor.
  • Oliver style tractors must also run a SFI 6.2 or 6.3 bellhousing with SFI inspection sticker in place. If they continue to run the OEM bellhousing they will be required to run a 6 buckle 4.1 SFI rated blanket.
  • All housings must stay in place, bolted ridged in all other chassis.
  • Auxiliary transmission will be permitted.
  • Skid plate must be mounted in-line with each frame rail and extend from the center of the front axle forward (on both sides) equal in strength to frame rail material. Skid must be securely mounted and braced to the chassis. Skid plate surface to be minimum of 4 inches wide and 12 inches long with a minimum 6-inch curve when measured from the front most part of rolled edge. Note: Skid plate must be able to support the weight of the front end when checked with jack. Maximum ground clearance is bottom of wheel rim not to exceed 4 inches with front tires in normal operating position.
  • Tractors must have a full running frame rail from the axle housing to the front of the tractor or tie bars running from the axle housing to the frame. The tie bars must be able to support the weight of the tractor with all of the bolts from the transmission housing removed.


  • All hitches will be minimum 3 ½ inches long X minimum 3 inches wide at the hook point. Vertical thickness of hitch will be maximum of 1 ½ inch minimum 1-inch cross-sectional thickness. Hitch will be no shorter than 18” measured from the center of the rear axle to the hooking point.
  • Maximum hitch height 20”
  • Wheelie bars independent of hitch. Must be able to lift tractor with jack under pad in heaviest class tractor participates in. Pad to be no more than 10” above ground and should be minimum length of 32” from center of axle when set at the 10” maximum height.
  • If the drawbar has provisions to be made SHORTER than the legal length (18 inches from the center of the rear axel) is not acceptable as a legal drawbar.


  • Maximum tire size 30.5 X 32
  • Minimum tire size 24.5 X 32


  • Acceptable fuels are diesel fuel, alcohol and gasoline.
  • No oxygen carriers or combustion accelerators will be permitted.
  • No ether starting aid can be on tractor.




  • Complete fire suit, fireproof gloves, head sock and fire shoes are required. Must meet SFI spec 3.3c. All drivers will be required to use a SFI approved 3.3 neck collar.
  • All competitors will wear a full-face helmet. Snell 2005 rating or better.
  • All tractors will have SFI approved clutch/flywheel assembly. No cast iron.
  • All tractors will use a six buckle 4.1 SFI approved safety blanket.
  • A safety light system is required. A white automotive quality light, minimum of 2” in diameter, must be directly mounted above or below the safety kill switch at the rear of the tractor.
  • The light is to be activated by a shift lever such that it will only be illuminated when the tractor is in reverse.
  • Must have at least 2 ½ lb. Fire extinguisher and be convenient to the operator.
  • Roll cage is required to meet SFI 47.1 requirement. 5 point SFI harness is required.
  • Side panels, firewall, and fenders are required on all tractors.
  • Fenders must be constructed so that when the driver is secured in the competition position no part of the driver’s body can touch the tire.

ATTENTION: If you have any questions on the rules above, please contact someone on the rules committee. Ask before you build, rules are subject to change.

Rules Revised 1/10/2017

Rules Committee

Brad Powell (502) 773-7505 – Bluegrass Pulling Series

Kevin Fulks (859) 391-2991 – Bluegrass Pulling Series

Scott Spiegelberg (920) 538-0642 – South Central WITractor Pullers / WTPA

Ed Shoobridge (810) 300-0454 – LLSS Traveling Series

Faron Reding (716) 640-8932 – Western NY Pullers

Ron Bailey (440) 821-0557 – Ohio LLSS

Steve Jennings (810) 287-2178 – Thumb Tractor Pullers

Tom Isenhart (269) 720-8090 – Mich Truck and Tractor Pullers

Tim Rydel (616) 835-3440

Wayne Stine (231) 409-9228

Greg Lussetto (308) 279-0232 – Nebraska TractorPullers

Doug Voth (940) 727-1535 – Texas

Andrew Armstead (810) 937-6493 – LLSS Travel Series