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Pro-Stock 4WD Truck Rules

TNT Truck & Tractor Pull

Pro Stock 4wd Rules


1.  Any truck body, any factory frame.

2.  Any single 4 barrel carburetor. No stretched carburetor. No tunnel ram or sheet metal intakes.

3.  Engine:

A. 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, No JC51, No DRCE3 blocks. Can be cast or aluminum block. Engine can be no further forward than 12 inches from front of block saver plate to center of front axle housing.

B. GM may run any conventional port designed head. Ford may run an “A” style head only. Dodge may run a B1 head only.

C. Conventional port designed head is classified as a head with the port spacing that must be left to right. No spread port or Billet heads allowed.

D. 1% tolerance on engine measurements.

4.  Headers and open exhaust allowed, must exit through hood or down and back.

5.  Body Specifications:

A. Factory wheelbase may be shortened or lengthened to maximum 134 inches. Bedsides may be altered in front of wheel wells to match wheelbase on all trucks.

B. Rear wheel width cannot be narrower than 34 inches from inside bead to inside bead of rear wheels.

C. OEM fiberglass components only. Front clip on truck (firewall forward only) can be fiberglass.

D. Front windshield must be OEM type (no Plexiglass)

6.  No working hydraulic stops on front suspension during pull. Must have quick disconnect and shall not be touching spring or axle housing before, during, or after pull. Weight boxes must stay stationary before crossing the scales and cannot be moved until after the pull is over. Any air pressure adjustments require a re-measurement of hitch height.

7.  Any street legal tire may be run measuring up to or less than 33 inch measured height. Terra and Cepek tires allowed along with any bar tire up to 31x15.50x15. No recapped tires allowed. Must have size on sidewall by manufacturer.

8. Any transmission, transfer case, front end, or rear end allowed. No planetaries.

9.   Hitch:

A. Hooking point has to be horizontal on hitch.

B. From point of hitch to center of rear axle shall be no less than 36% of trucks wheel base, i.e. 134 inch wheelbase equals 48.24 inch hitch length. Hitch heights to be 26 inches, before, during, and after pull. Hitch must also adhere to general and safety rules (see hitch qualification section).

10.  All Pro-stock trucks are to have adequate brakes; drive shaft brakes are adequate.

11.  Must run Spec fuel only. Sunoco-Purple 110; Blue 112, Orange 114, Red 116, V.P. C-12, C-14, C-16, Torco 112, 114, 116. Alcohol must be pure, no additives of any kind. Must pass water test. No Scent or Top Lube. No pro oxide, no pro blend, no oxygen carriers of any kind, no scent additives.

12.  All trucks must have a fuel dump valve for random fuel testing.

13.  Weight on class is 6200 lb.

14.  Trucks cannot exceed 102” front and back. Measured from the widest point, overall width.

15.  Auxiliary engines may be used, but must not be running while truck is in competition.

 For a printable version of the Pro-Stock 4WD Truck Rules please click the link below!

Melanie Wiley,
Aug 25, 2018, 12:35 PM