jeffro22

trying to do a simple job and it has turned bad. i was replacing the header gaskets on my 94 cobra. Well, Mac headers are nice when they are new but the pOS design lets them warp and when I removed them from the heads they woudln't line up again. I ended up messing the thread up on my AFR 165 heads (drivers side closest to firewall)The header bolt wasn't staright and i turned it maybe a trun and it got tight. So the thread is messed up now. How hard is it to repair this thread on the alluminum head/

r.barn

Not hard at all after you tear down the whole engine to get the head off.

jeffro22

can't it be tapped or repaired while still on the car. With the headers off it looks like there is enough room to get to it???

FivePointOhh

remove the header completely. go to autozone and buy a thread repair dye for 5 bucks at the proper size, rethread the hole and your done.

i had to do this time mine couple weeks ago, the thread as always kind of messed up but it finally cross threaded so i decided to fix it.

ACE

My heads effed up my header bolts not the threads when I put my gaskets on. Horray for 69 Cast Iron!! haha

moterhead

It's not "dye". That what ladies use to change the color of cloth. It's die, except a die is not what he needs. A die is for cutting threads on the outside. A tap is what cuts internal threads. They are called TAP AND DIE sets. I've never done that exact job, so don't know if it's SAE or metric thread. Suspect it to be metric. Take one of your header bolts with you. It's surely worth a try to see if the retapping can be done with the head on the engine. fivepointohh says you can. You might want to tape over the nearby port to keeps your metal pieces out. Good luck with it. I know how your feel!

rover420

Or u can always go the roughneck way just drill out ur manifold holes out a little bit and tap one size up or go metric or imperial up which ever it is. You Probably won't even have to take the heads off i did on my old chevy block once b4 but it was for a diffrent thread. well if there aluminium heads that is, if they're iron have fun.

drhoward

I would think you would be able to do it with the heads on, there is actually quite a bit of room in there

I have the same problem with one of my header bolts I was waiting until the spring to fix it, let me know if you do it that way and have any tips[8D]

tinman

I agree with Motorhead on this deal.
Head needs to come off the car as ANY drilling/tapping needs to be perfectely plumb....

92GreyGT

I would at least try to chase the threads before you go taking the heads off. Take the header completely off andget a 3/8"-16 tap or you can buy what is called thread chasers. Be very careful and take your time putting the tap or chaserin the hole. Turn it in a half turn or so and then back it back out. Keep doing this until you get it all the way in and hit bottom. Don't force it and try to keep it as straight as possible. If you mess it up worse, then you will have to take the head off and put a heli-coil in it. Finesse is the key here.Good luck.