'71 Duster 440 or 360? Pros and cons

I have a '71 Duster. I just bought it a few weeks ago. The car currently has a 360 in it with a 904 tranny. The 360 is pretty tired and is probably ready for a rebuild. I picked up a 440 last nite on a whim for only $375. It is complete and said to be running. I would probably rebuild it anyways. The 440 is a 75-78 motor, so nothing special. It did come with a Performer intake. I have no idea what is done to it internally. I am sure it has been rebuilt at least once already as it has a tag from a local engine rebuilder. I am curious to hear what you guys think about my situation. Is the 440 swap going to be worth the time and $? I have never driven a big block Mopar before. I have certainly never stuffed one in an A body before. Is it going to be more worthwhile to stick with rebuilding the 360??? Opinions appreciated. Thanks.