Does a 1971 Duster require inner fender cutting?

Quick question, sorry if its been answered already... you folks have sooo much info to read!

We just picked up a set of cars for a 1971 Duster project, and they both have inner fenders cut for the 440 engine. I have the cutout pieces and would rather the fenders are intact. Is it mandatory to cut these out to fit the 440 or is there a header that will fit?

Thanks and have a great day!
~Dale