I am trying to center this angle on the tubing, but I can only get the dimensions to be in the ballpark over/under 2.48/2.49 and 2.5ish. I have been trying to distance mate the outside edge of the angle to the side edges of the tubing, but it will only sit around the dimensions in the photo. What can I do, if anything, to center the angle on the tubing? 

Sorry for the blurred images, I couldn't figure out how to get clearer resolution.