i just did my plugs not that long ago, yes i took the head off, yes i used the old wires. I have had abo****ly no problems, jstu be sure to get all the bolts back in tight, adn there is a bolt or 2 on the back of the manifold that is hard to get at, but it can be done with only a socket. if you do remove the monifold. get a new gasket. and if it makes you feel better, new plug wires to. i didnt get wires becuase i was on a budget.