I broke two studs off to where I had to drill and helicoil them. They are the second ones in from the front on both heads.

Hows the best way to seal them up. Stock 915 heads?

Thanks for your time.

I used the red aneorobic(sp?) sealer, and also put the same stuff on the outside of the keensert I used instead of helicoil. It sealed.

I use liquid teflon thread sealant... never a problem.

The fact you have helicoiled means you now have two sources of leaks since there are two sets of threads in each hole. I would apply sealant fairly liberally.

Well I tried putting some ARP sealant and running the bolt back in.....done this twice to try and seal it. I went ahead and pulled the headers back off and took the helicols out and going to put some keyserts (I'm not sure why they are called that, but I think they are way better that helicols).

Drill a 29/64 hole for the 1/2-13(which is the thin wall kind) to go back to the 3/8-16 bolt. If it isn't one thing it's another.

Helicoils were made mostly for blind holes.Keyserts are made for open holes.I did heli one hole in my 516.I used the red locktite and then antisieze on the bolt.Never leaked.If you can use a stud it will seal better than bolt.Rocky

The best sealer I have found for the exhaust bolt holes is from Toyota. It is a good high temp sealer. Works way better than any thing mopar came up with that I have seen. I was turned on to it by a transmission shop here. He had a bunch of tubes of the mopar sealer he said I could just have if I wanted. He wouldn't use the stuff any more. Comes in a good sized tube so you have plenty for other applications. part number is 00295-01281 if you are interested.

I'm still not having any luck.