I think if you add about 200 lbs to that 4,500, you should be in the ballpark for a dry boat. Then gear, trailer, fuel etc...they get up there. I figure my towed weight (266BR with 496mag) to be up to 7,000 lbs if you were looking for that kind of info.
O'
"Little Mascara 3"
266BR,496 MAG-Bravo III