I hit over 160 mph in my 5-speed manual 86 GT convertible (with roof down) back in 1995 racing a Porsche 944 Turbo from 80 mph on the freeway. My car has an A-trim Vortech blower (8 pound pulley) on a otherwise stock motor with 3.55 gears and a BBK 170 mph speedometer (car also has equal length shorty headers, off-road h-pipe and MSD 6AL). The speed was still climbing when I got out of it when slower traffic ended the race (8 car lengths ahead). The car was very stable at that speed (not lowered at that time, but had a Dugan racing spoiler on the trunk), but the side mirrors were shaking violently. Very stupid on my part, with no roll bar, or helmet on a public road (marked for air surveillance) on a Saturday afternoon. A very similar equipped (but with stock 2.73 gears) 86 Mustang averaged 190 mph in the Silver State Challenge that same year.