Can I heat up the head to remove exhaust manifold studs on a 3406B?

Add a vote for welding the nut on the stud, then using it like the head of a bolt to back the stud out. Done this a ton. It's the best way I've found.

 

Yep. Tried and True many a time.

Of course you can soak it with PbY for days first And than heat it and fight with locking down some vice grips on it for an hour until the stud is completely round and your knuckles are Bloody and your 5 different ways of pissed off .

 

Keep your easy outs/extractors in your toolbox for a screw that moves. Drill out the bolt and helicoil if you cant save the threads.

 

Here is a very good option and way cheaper than screwing up a cylinder head. https://www.monacotool.com/Product/Detail/broken-exhaust-manifold-stud-removable-kit-cat-3400-heads/

 

I would pay someone to weld the nuts on it. You break off that easy out, which you will if you couldn't move it with a pipe wrench and than you SOL.

Helicoils are a royal pain. If the drill bit walks off center of the bolt than your hole is out of position.good luck ever getting a proper torque on it after that.

 

Drill a hole in the stud before welding the nut on it, weld only inside the nut (use a 3/8" nut) soak it with water to cool it after its welded so it contracts a bit then back it out nice and easy with a wrench or socket. You might break the weld holding the nut a few times and have to weld it again but just keep after it.

 

I had 4 broken exhaust studs on my 3406b I welded nuts onto them and still was unable to remove 2 of them, I heated the remaining 2 with the nuts welded on them and I got them HOT like red around studs, I was worried id do damage but it didn't it takes more than heating a small spot to do damage to a big piece of iron like that.