Quick question about speed and rpms

[maroon_98_RS]

First off My speedo is broken. If any one somehow just happends to know this or is realy bored. Could someone tell me about what rpm is 55 mph and 70mph i would greatly appreciate some help here.
forgot to mention its a 2g n/t manual

 

[eclipsemustang]

i think it may vary slightly from car to car but on my 95 GS it was 2800 at 70 not sure about 55mph though