413 or 383?

I have a 413 in my car right now that has maybe 1,000 miles on it and ran a best of 13.05@ 105, but im picking up a 383 that also has 1,000 miles on it and it runs pretty strong also...so should i swap the 413 for 383? Thoughts? Yay or nay? Header clearance would be better i know with 383 since my fenderwell headers are cracked and rotted and i have a b-body set.