42RH / A-500 in a Duster with pictures.

Do I need to run an adaptor plate to mate the 518 to a 5.7 Hemi?

I have seen several threads and I can not confirm for sure if this is needed. Street and Performance shows and adapter kit but I am not sure its for my setup.

I have no idea, though I'm told the Gen III Hemi has the same bolt pattern as a small block mopar and just needs a flexplate which Mopar Performance sells.