Good Afternoon All. I have a tech question about a stock SBC Cast Crankshaft. In some of the "spec" lower hp sprint classes around the country I know some people still use stock cast crankshafts in their race engines. I am curious as to if every stock cast crankshaft needs the rear flange machined to fit inside the motorplate hole and torque ball housing (i know without the machining that sometimes the flange will rub on the inside of those)? I had measured from the rear of a stock cast 305 crankshaft that had been machined and the largest diameter of the flange was 4.9". I am also curious as to what the maximum diameter of that flange could be for it to still fit without any machining done to the motor plate and torque ball? Thank you.