Intake manifold removal problem

[black_demon69]

I managed to get the intake off, we grinded off the bolt heads through the wheel well and pulled (with lots of force) ended up taking 2 inserts out along with it. But now that I got that off there's plenty of corrosion on those 3 there's no way they would have spun how it was. But now I have room to move I got wd-40 sitting on it, heat, and vice grips for my first attempt if that fails weld some kind of head on it and keep trying, currently stuck with rain but hopefully some more progress will be made. I'll try to remember to grab a picture before I start removing so you guys can see what it is.

Thanks to everyone pitching in ideas for me!

put antiseize on the new bolts that way next time they will come out. might also try stainless steel replacement bolts so head doesn't rust off.
when heating whats left get them red hot then cool them off very fast with water then heat them red again and turn out with vise grips. also helps if vise grips are new with no wear on teeth in jaw.