Hello. Wouldn't that would be a 1+2? :headscratch: There isn't any mention of 63C for Mustangs in the Ford master parts catalogue for 65 or 66. There is a 63C T-bird interior, but, no 63C Mustang interior. This tells me that Ford didn't make any bench seat fastbacks. It is possible that some dealers made that swap for a customer, but that doesn't count when talking about factory options. I've seen a few bench seat fastbacks, also, but, Ford didn't do that.No it never was offered on the Fastback because Ford called the Fastback a 2+2, will it fit if you wanted to make it a 3+2, yes... But it was never fitted from the factory in a production Fastback.