Manifold bolts?

[BlitzK5]

I just pulled my manifolds off my 454 to re-tap the threads on the collector. The bolt used to connect the manifolds to the engine look like just any old grade 5 bolt, and there shot. Are regular grade 5 bolts suppose to be used or are there special type of bolts needed due to the heat. Aslo since I got them off should I upgrade to headers or is there not much point for a 454?

 

[trailblazr81]

Ive used regular bolts. Just stay away from nuts with the nylon lock crap in 'em. Those will melt and ooze out. If you got the Green To Make The Scene, I would definatelly get Headers. Just also buy some quality gaskets, and know that you will have to occasionally check and tighten the bolts to prevent leaks. Help improve your motor's efficiency...

 

[BlitzK5]

opps sorry I ment the manifold bolts use to connect the manifold to the heads. My bad should have read my question. I will Edit it.