This 1950 Ford Flathead is in for a stock rebuild. In 1950 the Ford Flathead was 239 CI and had a 3.750 stroke and made 100 HP. The Mercury Flathead was 255 CI with 4.000 stroke and made 110 HP. In the early days of Hot Rodding some builders would use the Mercury crankshaft in the Ford engine block to get a bit more horsepower. Yes even in the early years people were building sleepers.