What's required to do this? I have one bolt that goes in cockeyed for some reason. I pulled out my header and drilled the header hole larger thinking that was causing it. No such luck. It still seals fine but it worries me. Anyone ever experience this? Short of pulling my engine and having it redrilled what are my options?

 

Which hole? That didn't sound right It might be tough with so little room. You can try chasing it with a tap. If that doesn't work the best thing to do is to remove the head and heli-coil it.

 

That's a lot of work I was hoping to avoid. If I remove the header there is a lot of room to work with. Where can I buy a tap?

 

Most hardware stores sells taps, usually next to the drill bits. Since it is aluminum use lots of lube and go very slowly. Turn the tap until there's resistance and go just a notch further, back it up, and repeat until you get through the bad threading. If this doesn't work (you must be straight and "with" the existing thread) you will have to drill it anyway to heli-coil so it's worth a try.

If you've never tapped anything before you might want to drill and tap something just to get a feel for it before attacking a cylinder head in the car

 

You can try using a longer header bolt to go deeper into the good threads by calling ARP to order one or just look around for some. Did you check the thread of the bolts to see if that is busted or the threads on the header bolt hole?

If you can drill the hole bigger on your head without pulling it than you can most likely do the heli-coil. If that is the case, I would go with the heli-coil since that works really well. I had heli-coil for head studs before and it is pretty common to do this. Header bolts shouldn't be a problem for the heli-coil.

good luck

 

Yea like hugh said heli coil is not that hard... I stripped both of my tranny mount bolts (I don't know how the hell that happened) torquing them in. I got them heli-coiled and put studs in. If I were you I would first try some other things... i had that same problem you are having getting my bolts in but if you did not strip the hole yourself then it probably is not stripped. Don't go removing the head and then find out that the hole is good. Make sure the gasket is not pushing the bolt for one and make sure the hole is centered. I also drilled mine and it was still doing the same thing but I eventually got it to work. I picked up this piece called and exhaust flange separator I believe from carquest and used it to widen the gap between the primaries on my driver's side for one of the bolts that didn't want to go in. For the other the gasket had to be shifted over just a tad (it looked good when I gasket matched it too). On the passenger side I drilled the header holes out and they went in.

Moral: Don't give up on trying to get the bolt in straight. If it just wants to start crooked I'm 99% sure you just have to mess with it a little to get it in. Do some experimenting, be creative. Try putting the bolts in the head in a different order or something. If the threads are messed up farther in the hole (which I doubt from the way your post was worded) then try tapping it but I'm just warning you to try everything you can before jumping to removing the head to heli coil the hole

Good luck.