No, you could have a heck of a time on the cast iron head too. # 5 GP on my 300D sheared off and it was a bear to get the rest of it out. Had to remove the oil filter housing and drill most of it out, then pull the injector and vacuum out debris. Just a little stressful! I'd give them all a shot of Liquid Wrench or similar every day. I used a copper based anti-sieze on the new ones, too. Nothing like drilling into a perfectly good engine to make one cautious!

Fred