I don't think anyone would argue that you should fill to the proper level and have no more fluid than you absolutely need. Let's face it, in a drag race environment, most want the least amount of fluids to properly get the job done. Even if you didn't cause any damage to the unit, you certainly don't want to be venting ATF all over the track.

But as far as any catastrophic damage from being one quart overfull? I have never seen it. Burn the unit up in 100 miles? I never seen it.

My .02, but then again, what do I know?

MB