B&M 10241 Flex Plate

Can you clarify what you are looking for. Is your engine a LA 360 or Magnum 5.9 engine? The B&M 10241 is for Magnum balance.
Mancini racing is supposedly selling a version of this 10241 for Magnums. Their website listings are mixed up so have to call them and be very specific about which engine you are running. When I talked with them in person the sales guys kept finding the LA part, but eventually they confirmed the Magnum part is available under their own brand. They did not have any on hand for me to personally verify that is correct though and it is expensive.
Just bought it from Mancini, hopefully they send the right one.