Slant Six 225 Exhaust manifold question - need help

Can anyone tell me if there would any problems or adjustments that would be needed to put a exhaust manifold from a '68 Dart - 225 onto a '64 Dart 225?
Should I replace both intake and exhaust manifolds at the same time?
Will the original '64 intake manifold work with the '68 exhaust manifold? Both engines are the 225 - just one from '64 and the other from '68. I wasn't sure if engine modifications were made when they changed the body style. Thanks in advance for your help