Jeff, these guys are giving good advice. The '68 covers are chrome and were the last to not have the oil filler cap. They were just the same as the '68 Z28, and were chrome versions of what was used on the other '68 small blocks. The raised Chevrolet script was only used on the '67 L79 (same as the '67 Z28), although the raised script was also used on many painted 283 rocker covers from '57 - '67. The '62 - '66 327s had a rocker cover that were sort of 'concave' except for a little rased rectangle in the center where the black & gold 'Turbo Fire 327' decal went. On those applications they also had a separate decal near the edge that spelled out the horsepower. that was done away with for '67 when the air cleaner got the red & 'chrome' decal with 'Turbo Fire', the displacement and horsepower all together.
Currently the only type that are being reproduced are the early 327 type with the concave top and rectangle for the decal, which is not right for a '68.
I am not sure about this, I'm only wondering out loud, but I wonder if 2 right hand side later valve covers with the PCV grommets are equivalent to the '68 style? If so they should be easy to find, but not in chrome. That you may have to get done yourself (if you are a purist).
BTW I've heard that the '68 L79 did away with the Holley and used a Rochester Quadrajet instead, at least on Corvettes. Is this a fact?
[This message has been edited by Cam (edited 12-17-2001).]