Trying to remove the exhaust manifolds on a stock 454. All the heads on the bolts are completely rusted off, GONE! You would think the manifolds would slide right off but the studs must be rusted to the manifolds. Any suggestions how to get them off. I'm not trying to save the manifolds.

heat

drill them out.

or if they are actually totally gone soak them woith wd40 and start smacking the manifolds with a mallet

If you do not need to save them, then hit em hard on the sides with a hammer. They are made of cast iron and will either give way or crack. Keep going till you are done.

Tried

Burn the heads of the bolts off with a torch. I've done it many times. Less than 30 minute you'll have both manifolds off.

YOUR NOT LISTENING! Just kidding, I appreciate all the input. The bolt heads are completely corroded off, there's nothing to burn. The manifolds must have rusted solid to the bolt stubs. Tried hammering off , just short of a sledge hammer, but I didn't want to damage the heads.

Grind every bolt head to make sure there is nothing left holding the manifold on. Strike it with a mallet.

Hose it down with WD-40 and hit that Mutha!!! Not being a smart Azz but you do have all of the bolts out right? Some of them may be rusted away so you can't even tell they're bolts!!

GET MEAN WITH IT!!!!!

Short of busting the bolts off in the heads I don't think you'll hurt them. If you do....then you get a new set of heads and have some work done to them, new cam.....you now upgrades