i have a new shorty header comming to me. I hope this doesnt happen when i go to put it in..

It wouldn't hurt to spray some good quality, penetrating oil on the bolts about a half hour before starting the job.

^ i was thinking the same thing.

Anytime you "break a bolt loose", it should start moving with less resistance... Steel bolts in aluminum can cause a problem, however if you feel the same resistance after you break it loose, start "rocking" the bolt,(turn it back in a bit, then out, then in, then out a little more, then back in, then out a little more, then in, then out a little more...etc...using lots of penetrants along the way... I use PB BLASTER) until you feel the bolt "free" enough to back it all the way out with little resistance.. Patience is the key! Take your time getting those bolts out to save much more time & money extracting them.
GL

Mine was broke off before, and the only way I found out was putting a header in.

drill the bolt on center all the way through, with a bit smaller than the bolt, then soak with pb blaster and use an extractor to remove. If it still wont come out, drill it the size of the bolt, then tap and helicoil.

you would have thought by now that there would be a better option then putting a steel bolt in an aluminum head. maybe some anti sieze on there? i guess they never suspected people to remove the manifold.

SKEETER , did you see a significant power gain with the header on?

There is, and always has been: Studs & Nuts... That way, there is no need to remove the steel threads from the aluminum heads.

ARP makes a stainless steel stud & nut kit.

I used a stock replacement because I already had a cat-back exhaust. The long tubes make more power, but I didn't notice any substance increase in the seat of my pants. All of my mods as a whole made my 3.5L come alive.