hhhmmmm!!!! 165MPH
I've had five RST's over the years from fairly standard ones to low compression, 230BHP cars and none have ever got up to that kind of speed (not without trying)
Quite frankly though you should never trust the clock on a MK4 escort cos they only read up to 140 anyway. I've had my stage 3 cossie up to that kind of speed and even then i dont think it was actually going that fast as most factory clocks overread a bit.