They are scammers!! The reason their deals seem too good to be true is that they are. They will take a deposit and you will never get your engine.
Luckily I checked them out and when couldn't find them on Google Street View and noticed that their accounts were dormant last year I didn't buy. The business in their supposed address, Central Auto Parts, told me that they don't exist and are ripping lot of people off. Be warned and warn others!