Originally Posted by Jordan Y.

On the firebird, there are 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, and 19 mm bolts/nuts, just to name the ones I've run into today, and also a wide range of standard bolts, 1/2", 5/8", 3/4", 11/16", and on and on and on. Sometimes, they use a metric size for a bolt, and a standard size for the nut that goes on that bolt! There's also hex head bolts, torx bolts, and other oddball fasteners in places that just don't make any sense.