Kim nailed it. .030 318 with 360 crank, mains turned down to 318/340 spec. Silvolite pistons with 1.741 compression height, with .065 milled off the tops. Then mill the skirts to clear the counterweights on the crank. You may be able to turn the counterweights down and neutral balance it and not have to fool with the piston skirts. Supposed to be torquey little things!
