Fuel Gauge Problem

[daveklein]

My fuel gauge reads way off......When I fill the tank it pegs the needle to the full side and then moves down but not even close to enuf.....It was still just on the full mark and I put 10 gals in it...I just put a new gauge on the dash but it's the same as old one....Is there any way to adjust the needle position?? Or do I have to bend the float on the tank sending unit ?? I hooked up the old gauge wrong one time..(hot one side,,ground on other side) so I thought I cooked it but the new one is the same ???? I really don't know if it worked correctly when I bought truck cause I've been repairing other issues from PO....Help ?? Dave..