In PRODUCTION, 1969 Z-28s and L-46 Corvettes used valve covers WITHOUT the internal oil drippers - part numbers 3932415 (left) and 3932416 (right). Some time in late 1969 (most likely) or very early 1970, these valve covers were replaced in PRODUCTION with valve covers WITH the drippers - part number 3965541 (left) and 3965542 (right). The early style covers, 3932415 & 3932416, were discontinued from SERVICE (parts counter sales) in March 1970 and January 1970 respectively so it is highly unlikely that any 1970 LT-1 equipped Camaros would have had the earlier style valve cover. I am aware of a very early 1970 LT-1 Corvette (original owner car) that was delivered in January 1970 with the second design covers with the drippers which is why I am inclined to believe that the change occurred sometime during 1969.
All of the above mentioned valve covers had an "as cast" finish and were definitely not polished. The color is actually more gray than silver and the surface texture is smooth (unlike some of the "restored" covers that I've seen recently). Also, the valve covers were side specific at this point in time since the right side valve cover was not drilled for an oil fill cap under the emblem as later revisions were.