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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 glance, but don't know the function or purpose of those little peaks.

Thanks in advance.
 

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Do not think they have an purpose, but interesting question.

I did some looking in my books & online to see when the "pent-roof" valve covers came into being.

Photo 1 shows the valve cover from a 1956 Pontiac, but this style was used from 1955-1958

Photo 2 & 3 shows the left & right valve covers from a 1959 Pontiac. Note the breather/oil fill locations, one up front and the other in the middle. These seem to have been used from 1959 to 1961, and possibly early 1962.

Photo 4 is the 1962 "pent-roof" des
1956 Pontiac Valve Cover.jpg
1959 Pontiac Passenger Side.JPG
1959 Drivers Side.JPG
1962 Pontiac Valve Covers.JPG
ign used from 1962-1966. In McCarthy's book Pontiac Musclecar Performance he has a section dedicated to the 421CI Super Duty. He has photos of the correct 1961-early 1962 421SD valve covers which have the same design as the 1959-61 covers with extended tubes to raise up the breathers. The correct 1962 421SD valve cover shows the "pent-roof" valve cover and the driver's side breather (like the 1959-62) mounted in the same position and on top of the "pent-roof" bulge.

I was not able to find an article I recall reading where it said the 1963 421SD valve cover had been chromed for magazine coverage and testing. But, my guess is that may have been the start of the chroming idea of the valve covers that ended up on the 1964 and up GTO's.

I may not be 100% on my presentation here, but it may answer the question as I would say it was just a matter of design change just like the air cleaners or any other part that goes through changes over the years.
 

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Discussion Starter #3
Do not think they have an purpose, but interesting question.

I did some looking in my books & online to see when the "pent-roof" valve covers came into being.

Photo 1 shows the valve cover from a 1956 Pontiac, but this style was used from 1955-1958

Photo 2 & 3 shows the left & right valve covers from a 1959 Pontiac. Note the breather/oil fill locations, one up front and the other in the middle. These seem to have been used from 1959 to 1961, and possibly early 1962.

Photo 4 is the 1962 "pent-roof" des View attachment 132561 View attachment 132562 View attachment 132563 View attachment 132564 ign used from 1962-1966. In McCarthy's book Pontiac Musclecar Performance he has a section dedicated to the 421CI Super Duty. He has photos of the correct 1961-early 1962 421SD valve covers which have the same design as the 1959-61 covers with extended tubes to raise up the breathers. The correct 1962 421SD valve cover shows the "pent-roof" valve cover and the driver's side breather (like the 1959-62) mounted in the same position and on top of the "pent-roof" bulge.

I was not able to find an article I recall reading where it said the 1963 421SD valve cover had been chromed for magazine coverage and testing. But, my guess is that may have been the start of the chroming idea of the valve covers that ended up on the 1964 and up GTO's.

I may not be 100% on my presentation here, but it may answer the question as I would say it was just a matter of design change just like the air cleaners or any other part that goes through changes over the years.
Thank you for the response and helpful photos. I figured this was an old question asked 1,000 times, but I guess it is part of Pontiac legend and mystery...
 

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Just a shot in the dark again and strictly conjecture on my part.
The Penta Roof valve cover design seemed to come out at the same time the new emission rules were taking place for PCV valves. California required them for 61 or 62 models. The Penta Roof design may have been a way to capture oil vapor.
 
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