I have a PRW on my 511" RB. It's an 8 bolt crank. The flex plate has holes for about any converter out there. It's been on there since 2021. No issues with it.

74 Challenger, bought it new. In 1978 I replaced the original 318 with a 446 and 727. Mild cam, Jardine headers, and Holley Sniper EFI.
New engine! 511" RB, Edelbrock Performer RPM heads, Eagle rotating assy, Comp hyd roller cam, Doug's 2" headers.