I screwed up my header install so I think I'm going to have to pull the head to tap the holes. Two of the bolts won't go into the hole and the last bolt that goes furthest back I believe got jacked up when I was removing the bolts. SO now I have three that were probably cross threaded.

Can I run a tap while the head it still on the engine or do I need to go ahead and just remove the head?

 

you can tap it while its in the car i ont see why not. or try a helicooil if that wont work.