I'm trying to get a new p.s. pump for my 81' Z28. The motor is not the original but when I got a new pump, the mounting bracket from the old one doesn't fit the new one. Checked the block casting #'s and they show the motor as an 80-85 lt duty truck motor so I got a pump for an 85 pick-up and the bracket doesn't fit that one either. Anyone have any ideas as to what could be going on?