my 2000 dodge van with a 5.9 and 3.92s is close to that fluctuation and it definately locks solid in lock up. It will not hold the speed as precise as my 2011 1500 ram did on the data stream on my scanner or in real life on the freeway running side by side.

I have a set of 3.21s to install, I am positive they will give me better highway MPG.