in my 2+2 I can definitely feel the extra weight in the rear with a full tank of gas vs near empty and that is a difference of about plus or minus 90lbs. So I'm not sure I can dismiss the weight distribution as negligible. Btw, which track was the NA good for you and which you got stuck at the top of a gear at? Do you think you could have achieved a faster lap time at that specific track with a TT final drive?