I'm not following? What would be the indication of the bolts being stretched? Also, if you have everything removed anyway, depending on when the last time work was done, I'd probably clean the surfaces and toss another head gasket on there. I know you have to do some other work to actually pull the head off, but I think I'd still go through with it. It's not all that good to crush a head gasket a second time, likely with more pressure if those bolts were stretched the first time. I wouldn't chance it.
i suppose you technically could. the problem lies in you have to disassemble everything anyway. you have to pull the cams to get the bolts out. so why not just lift the head off, change the gasket.