I spent quite a bit of time researching this topic and never found a clear answer. I think it was just for style, or to be different. I have not found any indication of function and have actually seen them installed backwards so I assume it was purely cosmetic.
Y'all have been very helpful in so many ways and I thank you for that help. I'm asking a novice question that must have been asked before but I can't find it in my searches. Why did the early GTO valve covers have a peak on one end? I want to make this stroker 467 look original at first...
This goes way back into the early sixties with the painted valve covers having the peaks. I don't know of any particular reason except for style. BTW, the 66 chrome valve covers are the same as the 66 painted ones used on all other Pontiac engines that year.
Peaked valve covers first started showing up in 1961. The same time California started requiring PCV systems. No positive proof but it has been thought that the peak may have been a way of collecting oil vapors for the early type of PCV.