421 4 mil cub very little clean up port, pretty much stock 421 cub, 39 pwk,s 180 main jet 60 pilot ,6 inch pods, fast cool head w 20cc cut domes, 200-205 psi each cylinder, +4 timing, staight cut over ride gears, 16 41 sprockets, c14 gas, shearer in frame pipes, soon to be cpi out of frames