Anyone have any great tricks for removing a stubborn head bolt? I tried to pull the heads on a Mark V 454 this weekend, and one bolt (there's always one) was so corroded the socket just rounded off the head. It was SO corroded in fact, I was able to tap a 7/16" socket onto what was left of the original 1/2" head, and for a brief moment, thought I had it. Then, of course, the smaller socket just rounded off what was left. What's the best option? Drilling, grinding? I vaguely recall attempting to drill off a head bolt in my younger days, with not-so-great results. I'd hate to trash the head...
Thanks.

I have welded a nut on top of a rounded off bolt before and it has worked. But I'm not sure if you would want to try that on a head bolt.

Weld a nut on top of the head of the bolt. Use a big enough nut so you can get a good weld inside the nut and to the top of the bolt. If there's room, use a nut that will go over the bolt head and weld it on. If you break the nut off, try again to get a better weld. I've been doing this for years and it works great. Tape off all the area's around it so you don't get welding spatter stuck to everything. If you don't have a welder, look into having someone with a portable one do it for you.

Craftsman has a set of removal tools called "Bolt-Outs". Have used them with great success on rusted/rounded off manifold and head bolts.

Dave

I've used the bolt outs and they work. Make sure you get the complete set, the one with 8 i think. I had several that wouldn't break free, I ended up sheering the heads off , then used a torch after I removed the heads.

I've use the nut technique several times with great success.

A little heat works wonders....

drill the head of the bolt.use same drill size as bolt

Ok but he asked about removing a bolt....

crasftmans make s afew good products

they the "bolt outs" that are like sockets with helical cuts inside them. When you crank it down the helical cuts dig into the head of the bolt and crank it out.

they also have "screw outs" you drill a hole into the rounded head and then run these things in. They dig into teh hole and crank em out that way.

You can also try a left handed drill bit OR a combo of a left handed bit and these heavy duty screw outs that snap on makes. They have big wide threading on them like teh bolt outs but functions like the "screw outs"