The cowl weighs in at 2 ounces, and since I have it off right now and its nose heavy, that would be 2 ounces to offset. I wont know how much will be needed until I get it back in the rig, but looks like I should be able so add some weight under the wing bolt plate, and behind the servos. When I originally balanced it, I had the Life pack slid all the way inside under the servos, and right now it is halfway in there, so that would be the difference in weight.