Flex plate issues

[Mopar471]

I swapped the 340 out of my 71 Duster340. I went with a 360 and the original 727. The issue I am running into is the correct flex plate. Its a 360, external balance. I have a Hughes tq in the torque flight. What is the correct plate that I should use? I have gotten different answers from Hughes, Jegs, Summit

 

[crackedback]

10236 iirc