goldengoat2

66 aluminum with 3767493 and "lester" written on the inside,,are these original?? thanks

zadspal

Why wouldn't they be? If the car is an early 66 and they do not have the casting seam through the "O" in Corvette they are originals. If the car is late 66 (built after April I believe) they should have the casting seam and are still originals. The casting number and Lester are both period correct for your 66 model car. The casting seam should be the defining factor. If you are asking, are your valve covers original to the car? Humm, you will probably never know. I hope this information helps.

ZADSPAL,

goldengoat2

Built in january and they DO have the casting seam

66since71

Correct? yes. Original? you'll never know. They were a common dealer parts counter item for years.

Harry

gbvette62

Which horsepower do you have? The 327/300 used a painted, stamped, steel cover. The aluminum covers were only used on the 327/350 horse motor in 66. January build might be a little early for the seemed covers, if it's a 350HP car.

goldengoat2

its a 350 hp

John BX NY

I think as the years went on and they continued to make parts on the worn out tooling the covers got more "ugly". The seam became more pronounced and the "o" in corvette started to fill in with flash in the center somewhat. Look at an original 66-7 part and a later repro and the difference is astounding.

jd

ctjackster

If Lester pn 3767493 and they are "correct" for your engine config (L79 - yes) and they have the casting "flaw" appropriate for your car's build date (such began appearing on L79s beginning at some point in the 66 model year, someone with their NCRS TIM&JG handy will provide precise date) then you are as close as you can get to concluding they are "orignial" to your car. If not orginal to your car, someone went to the trouble (or got lucky) to source "correct" valve covers for your car at some point.

By the way and FWIW, when I acquired my 65 L76 in 2003 (original engine car), it had casting flaw valve covers on it. Who knows why or how it ended up that way, I think no one really paid attention to that detail until the 1980s.

Jerry Bowen

My late-'65 (L76) has has aluminum covers, one with the casting flaw and one without. One or both could have been cracked and replaced at some point. Just had them lightly blasted with fine sand. They look fantastic.

GUSTO14

In 1970 I purchased a set of finned Corvette aluminum valve covers for my '63 from the local Chevrolet dealer for the whopping sum of $11 @... I should have bought a dozen sets!

Back then it was easier to buy these than keep the tin ones from leaking and everyone was doing it...

Yes they had the casting flaw, but as others have mentioned it wasn't as pronounced as it is now.

Good luck... GUSTO

Dad's 59

The casting seam started in 1964 Than you

JohnZ

Actually, it started in 1966.