on my 71 LT-1. To the best of my knowledge they are what came on the car,but the car has been through a few owners. The car is a very early prod. car and the valve covers have the 1/4 turn chrome cap, not the push in cap.All I read says it should have the rubber cap and I accepted that till I read of many early cars that received what stock parts that were left over. So could these be the right covers. Just curious.
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Re: LT-1 Valve Covers
B.,
Could be - depends on how early.
Terry
Terry -
Re: LT-1 Valve Covers
To B. Taylor, Does the oil cap have the S in the center? What is your vin number? BobComment
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Re: LT-1 Valve Covers
The VIN is....2709 built in the first days of December. About the "S" I will have to check after I get off work tommorrow. One thing of interest is that I checked the dates on the heads and they are from June & July of 70. I should check the date on the block for reference too. Still just curious.Comment
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Re: LT-1 Valve Covers
B Taylor------
Well, it's probably going to be difficult to tell FOR SURE whether or not your engine was originally equipped with the twist-lock oil fill, but I'll give you a way to help narrow it down.
Although all of the 69-77 small block aluminum valve covers LOOK the same, they are not EXACTLY the same. Specifically, the 1969-only covers were GM #3932415-LH and GM #3932416-RH. These valve covers had no drippers inside and were cast with either these numbers inside, or, 3932417 and 3932418.
In 1970, the valve covers changed. Externally, they look exactly the same. However, internally there were differences. Now, they were equipped with cast-in drippers for rocker arm lubrication. Also, and consequently, the part numbers changed. The 1970 valve covers were GM part number 3965541-LH and GM #3965542-RH. Inside the valve covers were cast the numbers 3965543-RH and 3965544-RH. BOTH of these numbers were cast inside of each valve cover
In 1971, the right side valve cover remained the same. However, the left side valve cover changed to incorporate the plug-style oil fill. The new valve cover was GM part number 3990994. However, beginning in 1971, BOTH valve covers started carrying a new CASTING number inside BOTH valve covers. These numbers are 3989005-RH and 3965542-RH(the same as earlier). This situation continued until the rubber plug-style oil fill was dropped(for 350s) in the 1973 model year.
After that time, the old GM #3965541 twist-lock style valve cover was BROUGHT BACK. This is a rarity in the GM parts world. Usually, once a part number is discontinued, it is DEAD FOREVER. Even if the part comes back, it comes back under a new part number. So, beginning in about 1973, the old interior casting numbers on the valve covers reappeared---3965543-LH and 3965544-RH. BOTH of these numbers were found inside BOTH valve covers, as was the previous practice. These valve covers continued in PRODUCTION until the end of the 1977 model year and continued in SERVICE until 1982.
In 1982, the valve cover part numbers were changed for SERVICE. The GM part number 3965541-LH cover became GM #474207-LH and the GM #3965542-RH cover became GM #474208. The interior casting numbers for these valve covers changed too. There were now 4 different numbers cast inside the valve covers. As I recall and without digging into my collection to confirm, the casting numbers are either 474207, 474208, 14025553, 14025554 OR 474209, 474210, 14025555, 14025556. It is also POSSIBLE that these numbers were cast into the valve covers sometime PRIOR to 1982.
So, the moral of this long story is this:
1) If your valve covers have no drippers inside(and no evidence of their being removed), they are 1969 covers and NOT original to your car.
2) If your valve covers have 4 casting numbers inside THE SAME OR SIMILAR to the 6 and 8 digit casting numbers that I provided above, they are later-issue SERVICE valve covers.
3) If your valve covers have the 3965543 and 3965544 casting numbers inside BOTH valve covers, they COULD be original to your car. Of course, they could also be replacements purchased during the 72-82 time period. So, you can't tell for sure if the covers are original to your car, but you can tell if the covers are definitely NOT original to your car.In Appreciation of John HinckleyComment
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