-Modified Class. Must look empirically like a mower. Must have upgraded steering and brakes suitable to the speed capability of the machine. Hydraulic or mechanical disk brakes required. Speed rated cart tires are allowed. Stock type tires must be in excellent condition to be allowed. Stock frames must be adequately reinforced and braced. Custom or tube frames are allowed. No restrictions on engine, transmission, or axle type, style, size or setup. Internally modified agricultural engines require a proper aftermarket flywheel designed for the rpm range of the engine.