Hard situation Head Threads strips

[canadianDisco2owner]

I m facing a hard situation, i m working on a P38 and one engine head bolt that i unscrew last night was very loose. I m pretty sure that the threads are busted. Does anyone had face this situation ? If so, i think to re-thread the holes with a bigger tap....my questions are; witch size tap i should buy and witch bolt from witch engine i should used ?

[TNRRClassic]

That's a common one. If you are pulling the heads anyway, you can do it on a press. If you aren't pulling them, it is a job for a 90 degree drill. Install a Helicoil and go on. I have seen folks use the thread former compound on one when they were selling one, but that isn't the solution. That is just a way to screw the next owner. Do the Helicoil and you will never have another problem with it. Be careful not to allow any shavings into the engine.

I think there might be some threads on Dweb about this.