[Agent_4573]

the 87-93 mustangs didn't come with the fuel shut off switch. Most modern day euripean imports come with a switch that stops gas flow if the car goes over a certain mph, usualy around 130. The only think like that hte mustangs have is the rev limiter, which only cuts off fuel at a certain rpm so you don't throw a rod threw your hood. Top speed is dependant on drag and how much horsepower you have. drag's main factor is weight and what the front of your car looks like. as we all know the fox body's were that aerodynamic but they have enough power to get them up around 140 anyway. I had mine going 135 at 4000 rpms up the highway, but 4th gear has alot ofpower over 5th. I would say there was maybe another 15 mph in 5th. It really depends on how much power you can actually put into wheels.