OEM means Original Equipment Manufacturer, which means the part is "factory" original, i.e. from Ford, Chevrolet, etc. On occasion, you'll see it used by suppliers who originally sold the parts TO Ford (or Chevy, etc) to identify the parts as the same as factory original parts, although they probably no longer have factory part numbers stamped on them. OEM essentially means "not an aftermarket part."
actually i thought the only dumb question was the one that guy asked about hooking his exhaust straight into his intake..
HAHHHAHAHA , yeah ST that is not the ONLY dumb question just by far the most idiotic, even that is not necessarily dumb, but Idiotic is when you have repeated people telling you EXACTLY why it is a dumb Idea but you go on defending it..