Ok need some info

It may sound stupid but I hear everyone talking about they have a mach 1 or a bullet or so on , how do you tell the diference?

I assume you talking about the newer cars like the 99-04 models. Well the Mach 1 will have the "shaker" hood scoop on it, that's the biggest indicator. it also has a 4 valve engine if you see it with the hood up. As far as Bullits, they came stock with a cold air intake and have 3.73 gears in them. Bullits are harder to recognize but there are some decal diffeences that are harder to get after market that you can tell if it's legit or not.