@Dartvader440gt Stay away from factory replacement. They are flimsy and will break. I had a bone stock 1976 318/727 flex plate break in my D100. After looking up the issue on here and posting about it, many people said they have encountered the same with the same point of failure. Make sure you use blue Loctite 242 and torque the flywheel bolts to spec.
Here is the best , most economical option
Mopar Chrysler SB 318 340 360 BB 383 440 Internal Balance Heavy Duty Flexplate | eBay