at 75mph i'm at 3200rpms or so, 80 is around 3500rpms. Maybe your speedo is not calibrated properly. I found out that mine was off by 7mph exactly at any speed (strangely enough my maxima had the same problem, same year. clocked with a gps nav system).
Alex
robo (sebring1970) - There's a Z saying that it is "easier to pull the engine than change the spark plugs"
Spee -the depths of your stupidity have yet to be found.