Ford Repair: Ford econoline van, ford econoline van, ford econoline

Question
Repairing a 95 e-150 with a 351. The starter bolts are frozen in the housing. I managed to get the starter out but cutting just the heads off. Now i have two bolt studs protruding and ive tried everything from direct torch heat( reddning the bolt and heat on the case as well) to peroxide and penetrating oils. They wont budge and im afraid to burn them out so not to damage the casing.

What would you do?
I appreciate you taking the time with my question.

Answer
You have options.However,do proceed with caution.If the studs are protruding out far enough,grind enough to be smooth and try welding a fastener to the end.This might give you an opportunity to get a wrench back onto the studs.One piece of advice is leverage.I wise man once told me that if I gave him a lever long enough he could lift the world.Another possibility is to drill out the old studs and to insert new threads with either a heli coil or a tap and die set.One thing to remember would be that you will need to keep the bolt the same size.