I'm not an expert, but i believe this issue is open to some debate lately.
Classic conventional wisdom is that the head bolts stretch a bit when you torque them and after they have already been stretched once, torquing them down again will lead to failures.
Antihero
Putting AMS garbage, and $500 ebay wheels on a Z is like dressing a Victorias Secret model in a Walmart dress and Payless shoes. You're embarrassing yourself.