Simply lining up the marks on damper and cam does not give you an adequately accurate indication of timing chain stretch. These marks are simply put there to be close enough to see that you get the chain on the right teeth of the sprockets.

There is a procedure in the repair and overhaul manual that tells you the exact measurement with a dial indicator over one of the number one lobes.

That said, if you hand turn the engine clockwise, slowly to top dead center on the balancer while on the compression stroke, stop exactly at the TDC mark and then look at the cam, if the mark on the cam is PERFECTLY lined up, you are most likely okay. If it is trailing behind the perfect match of sprocket mark and cam bearing stand mark, follow the dial indicator procedure to know for sure, or replace the chain.

Good luck,