4.7 exhaust studs source?

I talked to stage8 and they said theirs were header bolts so I was concerned with length.

I just got all 16 (goes from manifold to head) various ones at the dealer plus a set of nice shielded gaskets for 108 out the door.

Then amazingly the bolts were broke at the head in the rear passegerrs side (2) and the drivers side 1. When I pulled the passenger manifold the bolts were protruding like 1.5 inch and I unscrewed them with my fingers.

Drivers side one was broken on rear top, and I snaped the other rear trying to turn it. Then when I got the manifold off, same thing, broke under the head of bolt. I unscrewed the remaining part with my fingers.

I put all new but next time it will only be rears. I used a bunch of anti-seez on everything, torques to 18 ft lbs and it runs smooth and quiet.

I had pre soaked the whole afflicted area with a mix of zddp, gasoline and left over wd / liq-wrench mixture which I had gathered up in a spray bottle. So, everything was pretty decently saturated but of course the threads into the head were still dry.

Thanks for all the replies.