273 to 440 swap

I'm hoping Jim Lusk will weigh in on this. Well i've got the Transdapt mounts, but the 383 i had lined up, isn't happening, but i'm finding lots of 440's. Now i've been told that the 440 gives better p.s. clearance due to the taller block, so i'm now thinking 440. Would anyone that's done the small block to 383 or 440 in an A body, please give me the pros and cons. Much appreciated Gerry