Have a question about fixing this problem for good. I have a lot of bolts broken and a couple of them are even with the manifold. The truck is a 2001 F-250 and only has 60,000 miles on it. Some one suggested replacing the manifold with a header....Any suggestions? I plan on keeping the truck a while and do not want to do this again. Thanks

Soak them with P-B Blaster for a few days. If you have enough to get a hold of with channel locks try to use a stud remover or channel locks and get them out. You can always remove the head and take it to a machine shop to get them removed. Use new grade 10.9 bolts or studs and use a torque wrench.
Ask your local machine shop for their advise. Some use a thick washer and a mig welder to weld the washer to the stud then weld a nut to the washer and remove them. I never had much success on aluminum heads I got the studs out and had them fill welded using a mig welder with aluminum wire. Filed off and used a gasket and drilled a new hole.

Thanks for the reply, Not looking foward to this big job at all.

If the head is cast iron with 3/8 inch bolts I drill out the bolt with a 5/16 inch drill bit and retap with a 3/8 inch tap. Center punch the bolt first. I think they went from 3/8 to 8mm bolts is why they all broke with an aluminum head. I have drilled one or two and used 3/8 inch bolts some people use heli coils.

Don't Triton exhaust studs suck? I have had some good luck slotting them with a dremel and turning them with a power driver (the screwdriver-looking tool you hit with a hammer). Sometimes I get a little over-zealous with the dremel and get some of the head, but have observed no ill effects to date. Also, Ford has revised studs out, I usually helicoil to original thread when I end up drilling them, then I don't have five different sized sockets out next time I have to remove the manifold...I don't see how headers would help your problem, but if you want them, now would be the time. Good luck with it!

Yep going to helicoil them and looking at stainless steel bolts. I really don't want to do this again. Thanks again