If you post your rear end ratio, tire size, and tell me if you C4 gearing is standard ratios I'll print you a nifty chart you can use to compare. If you are considering different rear end ratios let me know which ones and I'll print you up a chart lke this
Interesting Question.....here is my RPMs by speed and gear with my 4.11 rear end and a 3k stall...I have driven through a few radar traps and my actual speeds are close enough to this chart for me to consider it accurate.