Dave I would say it would as long as the down spout sections you are using have a radiused edges along the length and they are flutted. Flutting is not as critical as the radius, the raduis allows the sections to seat firmley into the bracket. If you are using a retangular gutter with square edges along the length it would not seat firmly against the back of the bracket. I also install 1/8 inch dia. pop rivets one per side, strong winds have a tendency to pull the downspouts out of the brackets. RoboBeck2012
There is a 3 X 4 inch clip. The part (Model) number is 39029.
There is a 3"x 4" size available, but I'm not sure they have it at Home Depot. Lowe's carry that bigger size.