I recently had to do this to my car right after i got it. There is onyl one real way to do this. Soak the bolts and studs with a good rust eater. Do this for about 2 nights or so, then you have to use an acetyline torch to remove the bolts. I did this and still had one break that i had to have removed. The problem is the aluminum, inside the head/block the metal oxidizes, and starts to eat away the bolts a little, the real proble is that the oxidation binds when removing studs,bolts, etc, and then they usualy break.If you can get the manifolds off i would either replace all the studs, bolts etc, or reuse the studs , chance them with a chacer and use new nuts and washers. Grady sells a whole kit i believe. I left my studs in because I was too scared to try and remove them. - Shain [snipped again]