Valve train oil passage bolts

look down in the hole( 2nd from the front/back) and you will see how it's
made...the shaft has a little bit larger hole for this position and that's why they tell you Notch down and to the front on the right and visa versa for left.
It's the larger hole on the bottom of the shaft that your matching up...and all this is over if they didn't match the cam bearing up like moper said