From the timing chain?
I guess if it IS from the timing chain the chain is probably all sloppy and should be swapped out.
BUT, if you do decide to notch out the side try to not go so far as to go all the way through the side so it doesn't end up snapping off the end of the arm.
Imagine what could happen if a peice of it got between the chain and gears.
Probably snap the chain and possibly eat some valves. (If you were lucky)