What's the inside of your tank look like? If the pump is quiet when you first start it up, and then gets louder after you drive for a bit, the pump is probably restricted. If there's a bunch of sh*t in your tank, and the pickup sock is getting clogged, the pump will whine.
I had this issue on 1813. Here's what my tank looked like:
Pull the pump out and check the inside of the tank. Take a look at the sock as well and see if it is really dirty. A defective sock can also cause a restriction, and make the pump loud. The 255 in my car is fairly quiet. I can't hear is over the car running. Maybe if I had stock exhaust and the car was stock, but I can't hear it normally.