117 timing chain & guide rail issue

[delucat2]

Morning everyone.
I ran into a snag while getting things put back together after replacing the guides on the 117 in my 88 560SL. When I go to refit the driver's side cam sprocket, I seem to have lost about 2 cm of chain length on the lower chain that dives into the block, headed for the distribitor drive gear and the crank. I indexed both cams and the crank, so their relative positions have not shifted. I fear that when I had the cam sprocket off to replace the lower rail, I slacked off on the chain and it rolled over the distributor driver sprocket, and down under the crank. When I went to pull it back, it has gotten caught by the teeth on the crank, and created a bit of a loop of slack that I can't get back.

How do I recover from this?

Can i feed extra chain from the slack side of the passenger's side (where the tensioner naturally talks it up) through to the drivers side?

Or should I use a breaker bar to reverse the engine until I can "recapture" the slack, then place it back at the index mark?

I will be checking the cam inedx marks and crank timingby turnign her over by hand before I apply the key after this one to make sure there is nothing out of wack. Do not want to crack valves.

BTW - at 91k miles, the guides looked great, and were still very strong. I had to try to chip the upper guide that usually ends up breaking off and jamming the sprocket. Good material. Only about 1 mm of wear at the deepest groove in all 3 rails.

Thank you for your thoughts.
tony