Some boats because of bottom design are not good canadates for a set back pumps. Before you decide to set your pump back check with some of the guys on the boards with your style of boat and get some input on how the boat handles with this mod.Its a lot of work to move the pump back but it's a whole lot more work to change it back.
Then do the Reader's Digest condensed version. The way this thing has been setting on the plumber's night mare of a trailer, I'm sure it's out of whack. Here's the wreck of a trailer (?) and how the hull is sitting.