My friend tried replacing his timing belt on is 96 v6 toyota camry. He ran into some problems and it doesn't start. He said one cam sprocket somehow rotated an unknown amount while the belt was off. I was wondering if he could just point everything to tdc and put the belt back on would it work? Another thing is that the one cam sprocket has two index marks labeled 3v and 4v and he doesn't know which one he should use to represent tdc. Will it mess up the valves or anything if he tries both ways?

Thanks,
Brad