Tractor Year: 1970 AND OLDER

Age of driver:

Age of driver must be of age that will enable them to operate the tractor in a safe and proper manner. Those under 18 years of age MUST have a parent/guardian signed insurance waiver, good for the season, on file with OSATPA.

Classes: 3500, 4500, 5000, 5500, 6000, 6500 #


18.4 x 38 maximum allowed in all classes.  Cut tire allowed. No radials or no steel wheels. Two wheel drive only. Any width rim is allowed.


Any gear, speed limit 5MPH. Speed will be checked by radar. Shifting of TA's allowed..


Weights must not extend rearward beyond rear tires and cannot be more than 11 feet from the center of the rear axle to the furthest point forward.


Tractor engine must be stock or engine must be from original manufacturer and bolt in without modification using existing bell housing and motor mounts. Frames, transmisison, rear end and axle housings must be original or manufacturer's replacement. Stock heads and their replacements are to remain unchanged in outside appearance.  Dual exhaust not allowed except after stock manifold. Tractors must be naturally aspirated. No turbos or blowers - except 99 GM Olivers, etc. Any agriculture carburetor allowed. Number of barrels, throats, venture, etc., must be that of the manufacturer for that make or model. Interior enhancement of stock or manufacturer's replacement manifolds permitted. Enhanced electrical systems are permitted in all classes. No rev limiters allowed.


20% margin of error will be permitted. All tractors must have positive throttle stops.

Hitches/Draw Bars:

Draw bars must not exceed 20 inches in height or be less than 18 inches from the center of the rear axle. No part of draw bar may extend rearward beyond the point of hook. Draw bars must be stationary in all directions. No clevises. Hitch material cannot be thinner than ¾” and not thicker than 1.25”. Hitch has to a 3.75” hole with 1” material thickness around the hole or a straight clevis bolted or pinned tightly to the drawbar with a minimum of 3.75” hole. Top of hitch adjuster cannot be above center line of axle or hub. Hitches and drawbars must be stationary in all directions. Hitches or drawbars cannot be moved when pulling down the track.


Gas, diesel, or LP fuels only. No alcohol or nitrous oxide fuels may be used in tractors. Gas is allowed a maximum of 750 specific gravity. All tractors are subject to random fuel checks. Tractors manufactured to use diesel fuel only cannot be converted to gas or LP


No tubular frame rails permitted; must look factory (2021).

This site is owned and maintained by OSATPA.  2013.

OSATPA Division 3+ Rules