Which W2 castings are you working on? Race or Econo castings? when I put 9secondPhil W2 motor together years ago with the race W2 heads I don't remember any isuues with the rockers or valve train anywhere It was a low compression pump gas combination set up for NOS so he could drive it anywhere, it had a custom grind Comp Cams solid lifter cam in it also It did have the extruded aluminum Crane W2 rockers that Mopar sold back then so maybe that had something to do with the no problems