Mark,
It sounds like they gave you the wrong pump.
Also check the height of the hub from mounting surface of pulley to pump body where it goes in block. They're not all the same.
Parts books use to have measurements for this.
I'm assuming you're using pulleys for a 67 Camaro.
Did trucks get the bigger diameter bolt patter vs cars or was that a change from the 60's to the 70's?
