You paid the machine shop to do machine work on your zed. 3 times youve checked it and everything is in tolerance and bored correctly. So why are you going apeshit at the machine shop, sounds like they did their job properly. Unless they have installed the pistons backwards doesnt sound like they can do anything differently. Did you by any chance get the skirt coating on the wiseco pistons? Are you sure it was bored to NOT take this coating into account?