Broken Manifold bolt.............. Suggestions...........

[Got Torque Diffs]

I've been here to usually ill drill a center in the broken bolt then
Drill a hole just a hair bigger than the stud kinda cutting into the head,
But that second hole is just a hair like an 1/8 deep. Sthenuse a
Reverse drill bit... The second step help the resistance built from backing it
Out..... Trust me it comes out like butter...
We've gotten allot of oils well trucks from KEIWIT, and they
Always have broken studs all over the place because of the lignite rock
They are surrounded by.... It really fucks up metal...
Hope that helps

[Mickeymotormount]

My iron headed 6.0 had all 4 corner bolts broken flush with the head. I drilled a small hole through the center of the bolt. I then used a torch and aimed the flame right into the hole for about 30-45 seconds. After it cooled slightly, I used an easy out. They all came right out. Hopefully yours won't give you much trouble.

[zebra]

Prior to doing anything shoot some penetrating spray in there and let it sit. I would suggest doing this a few times then letting it sit
Should make getting it out easier.

this

It isn't gonna come out too easy because those bolts have yellow locktite on from the factory so i doubt penetrating oil will do much but welding the nut on might be a good shot because it gives you something to turn it out with and may heat up the locktite enough to break it free.

i sprayed my 10yr old factory bolts with PB Blaster once a night for a week getting ready for my header install, and every one came right out with no problems. i even reused them all & they're still good now.