1967 Dodge Coronet 440 not starting

My wife and I bought a 1967 Dodge Coronet 440 and it was running great while we were looking at it and we started it several times and all was good. We then drove about 50 miles north on the highways. We parked it and the next morning it wouldn't start. It turns over but it seems like it is lacking that little extra to get it going. I replaced the fuel filter and still the same story. Anyone have any ideas?