I installed a set of waterpump deletes last year and installed the water pressure guage line off the sea pump .I am getting 25-30psi at 4500 and more a wot has anyone else had this problem? I have a set of pressure dump valves on it and it helped a little but still high.

What pressure dumps are you using?? They might not be big enough. You should be running the Merc presure Dump #863208A-3
Here is what it looks like, and how it's been installed.Merc Pressure dump thread

The water pressure line should be read from the engine block. block pressure is what you are concerned about not what the pump see's. hook the gauge to the down on the bottom of the block where the drain is or at the top off the intake and see what you come up with. if the pressure is still high it could be that the intake needs to be shortend (if it has thru hull pickups) or there could be a restriction in the exhaust or other point after the heads.