I'm building a 1960 Thunderbird with an FE 390 engine. I'm doing a roller conversion. The cam manufacture suggested a melonized gear to match the cam. MSD tech told me that they can not tell me if their distributor gears will work on a roller conversion. He said that all MSD distributor gears are melonized. I need a part number or a phone number to an MSD tech that can help. Thanks.