This is more of a question----how many have installed a 401 or 425 in a 57?? If there has been--what were your problems if any doing the swap. This only concerns the engine bay area---I have already opened up the drive line so I was more concerned on any issues you may have encountered such as motor mounts or the like. Thanks!!

Just put a 401 in a 1950 Buick. Not sure how this will relate to a 1957. The biggest problem I ran into was getting the exhaust manifolds to clear the steering box. I had planned to use a power steering box. I had to scarp the idea of power steering. The manifold barely cleared but I tried 4 or 5 factory manifolds before I found one that would work.
One good thing that happened was the 1966 switch pitch trans would bolt up at the transmission mount which gave me the perfect clearance on my fan blade to the radiator.