No locked rear ends. Maximum cylinder bore .040 inch over stock. Steel or aluminum rim, width will not exceed the tread width of the tire. No tires may be over 23 x 10.50 x 12 inches in size. Garden tractor type tires.
Stock means stock motor on a stock frame.
Milled heads are allowed however, see the diagram for specifications. One factory type head gasket installed in the proper location. Camshaft can be any grind. Factory stock valve size, intake and exhaust valves need to be O. E. M. stock. Stock flywheel only.