Not an A body guy, but . . . Floor pan question

Another Mopar buddy stopped by the shop, he just got a 66 Valiant that needs a floor pan. Apparently there's not one specific to the 66. anyone know of what other floor pan might work? He was told by someone a 67 would work but might require some trimming. I know that there was a major change from 66 to 67. Any words of advice/wisdom are appreciated.

RT