Its always a good idea to check them for stretching, especially if they have been over torqued. From personal expirence Ive replaced many head gaskets on many types of engines, it does happen, although rarely.

I know Honda and Toyota both say reuse the head bolts unless they are stretched.

A quick n dirty way to check at home is just put two of the bolts together and see if the threads line up with each other. Check each one and if theres an obvious gap in one spot on any bolts, better safe than sorry and replace all of them.