What is your bell housing number? That dictates Flywheel. Not 100% sure on A12, but I thought your car would have the cast iron bell housing for the 143 Flywheel for external balance. So you use the standard 11" clutch. In 1970 mopar went to the aluminum bellhouse for the 130 tooth with 11" scalloped clutch (10.95" disc). Either will work, but the bellhouse size determines the flywheel and clutch.