This statement is the only reason I said something. When you stretch an ARP bolt to their specifications I do not think you are getting into plastic deformation. That may be different for new production bolts. Pictures to follow.
I was talking to my dad about this (structural engineer) and he was saying that the bolts are not torque to yield like some others, and because of this they only deform in the elastic stage, so they will go back unless over-tightened. He said (like others have said to) that the point of this is to keep constant tension, so the bolt acts like a spring and keeps its self tight. Now over time the metal does fatigue, but this take lots of time. From his standpoint he thought I wouldn't have a problem re-using them.
He said alot of things, and that is all I really understood! LOL
I find this thread really interesting, am learning alot from it.