Rick Hanmore

Most Olds 303 V-8's that I have seen have grooves in the valve covers, (side-to-side). I have photos of a 1949 wagon with the same engine, but the valve cover surface is smooth. (Both have the wire loom in place on the top). Is the smooth valve cover correct? Was there a change during the model year? Also, what is the correct color for the valve covers and the wire looms? Thanks!