PRW 1844010 Xtreme Duty SFI-Rated Internal Balance Steel Flexplate for Mopar SB and BB, 10" or 11-1/8" Converter Engineered to handle extreme duty applications Designed to take the punishment of todays high horsepower engines 4mm thick centerplate provides a solid foundation Ring gears are precision welded to meet SFI specifications, utilizing robotic machinery and cold-welding process