If you don't have an overdrive transmission, that would be a good gear to run. I run 3.80's in my Buick V6 powered Toyota truck with a Gear Vendors overdrive and 26" tires and it's OK on the highway. The diameter of the rear tires makes a difference when figuring out what gear to run. The stall speed of the converter can affect the cruise rpm also. Gear it too high with a loose converter and it will always be slipping some. I went from 3.25 to the 3.80's, and acceleration was a lot better, but then I needed the overdrive to drive it on the highway. It's always a compromise between street, strip, and highway.