Build it, paint it, how ever you want, drive it like you stole it, use what ever parts you find...
yes it can effect the value to an extent, if it was a std 383 car, I wouldn't worry too much thou...
{I've seen some people that estimates as high as 25% if it's not the OE color & not #'s matching},
especially to a die hard purist,
but if it's done correctly/tastefully, not some freakish color,
most people would look the other way,
you'll get the occasional fender tag decipherer, that will always make comments, just don't worry about it...
Unless it's a really rare color &/or a really rare car combo,
I wouldn't be too overly concerned about resale value,
it already has a 440ci, that it didn't come with....
Now if it's a 1000pt concourse restoration,
that will be judged to the hilt, then yes repaint to the original fender tag code,
otherwise I'd say do your own thing, have fun,
I always do...
Good luck