ORIGINAL: Kweasel
All of the fixed pitch GA airplanes I have flown tach a little higher at 8000ft than they do at 1000ft.
Wrong! You can go past redline flying level at or near sea level. You have to throttle back to about 3/4 throttle to prevent going over the redline. At some point you can firewall (or is it instument paneled?) the throttle and not go over the red line. Apparently you need to re read the tech links I posted.