Keisler's speed table on page 70 shows the huge impact its overdrive will provide. Just think-you'll actually be able to cruise in your Corvette and carry on a conversation without straining your vocal chords or your engine and save gas! Times are good. In addition, with fewer engine rpm, less fuel is used. As a result, your Corvette will cruise at higher speeds with less wear and tear on the driveline and your ears. In a nutshell, with an overdrive, the transmission-output rpm will be higher than the engine rpm, thus sending more driveshaft output shaft revolutions to the rear wheels with fewer engine rpm. For those of you who aren't sure what 'overdrive' means, the term refers to the transmission-output rotation speed versus engine-output speed.
