I know just what you're talking about, my D2 manifold is in probably about the same shape as yours. Exhaust Manifold bolts seem to be the worst, due to all the heating & cooling over the years they can fuse together and pretty much become part of the manifold. Don't expect them to come out easily. Vice Grips & easy-outs will just make the bolts mad. You will most likely need to break out some big-boy tools and just declare War on the #@&?!(^%)?! bolts.
When I restored my Jeep there were a lot of broken bolts in the frame, most with little to grip on and none of them would budge. I tried welding nuts onto what was left of the bolts but they would just break off. The best method I found was to just keep adding weld onto the broken bolts a little at a time until you have a decent size blob to grip on (that will also put a LOT more heat directly into the threads). Let it cool off a bit then use a small pipe wrench to unscrew the bolt. It works great!
Another method I have used on Cast Iron is to blow the bolts out with a cutting torch (ah, the old Fire Wrench). If you're careful and with a little practice you can burn the steel bolt out of cast iron and not harm the cast iron. The steel will melt & puddle long before the iron. Clean the threads out with a tap and you're good to go.
Last edited by zootownjeepguy; 01-26-2011 at 05:39 PM.
'46 Willys CJ2A Farm Jeep, '49 International KB-7, '31 Allis Chalmers U, Cushman Scooter(s)
Antique garden tractors & outboard motors
Other rusty old junk comes & goes without warning.
The 2 most useful tools to have in your shop are a Crystal Ball and a Magic Wand