I recently had a 401 nailhead built. I was prepping it for paint and noticed the rods were put in as if number 1 was on the front left bank. Number 1 is correct to the front right bank (pass side). The first rod to the front is marked #2 in the #1 hole. At TDC the cam is indexed correctly. I'm thinking rods don't care where they are as long as the caps match the rods. The complete assembly was balanced.