[blykins]

You really have to pay attention to the whole combination when you pick transmission overdrives. With a rowdier engine, a .64 overdrive will most likely put the cruising rpm in a spot where the cam is not efficient, resulting in the "buck."

If your engine is close to stock or very mild, then you could probably get away with the .64 over the .82. Everything plays a part though....cam, rearend ratio, tire size, you name it.

Most of my Cobra stuff uses a .82 OD if the customer goes with a TKO.