hi everyone, i'm new here, i'm in the process of rebuilding the engine of my 450 sel, but i got stuck lining up the cams to put the chain on, i asked before and they told me to put the no 1 cyl at tdc and line up the cam sprocket keys with the marks on the cam bearings, but i can't see any marks on the bearings (i see a few marks that look like casting marks), so if someone can help me out with the steps to line up the cams with the crank it would be great, i've been trying to do this for a few months now and no luck

cheers
aly