Both the 383 and 440 manifolds bend around the steering column somewhat like the small block manifolds do but because the 440's block is taller that bend needed to be relocated although I have seen 383 manifolds on 440's in a-bodies and they seem to fit. Also the drivers side manifold changed from '67 - '69 so Mopar gave them different HP ratings for each year but I'd have to go back and look to see what that rating was.