Yenko Camaros (1969) - Two! - Lemont, Il. 1969

[66 L78 ragtop]

1969 Vette L78?...No such animal

1965 was the only year that an L78 was offered in the corvette.

[Unreal]

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1969 Vette L78?...No such animal

1965 was the only year that an L78 was offered in the corvette.

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OK, bad example.

You said that the L78 Chevelle was a different engine internally than the L78 Corvette. I know you said the L78 Corvette was only available in 65, but the car in question was a 66 Chevelle. So to stick to the question, would the 65 Corvette L78 be the same motor internally as the 65 L78 Chevelle? (Z16)

What I'm really trying to learn is if it was "normal" for same coded motors (eg L78. L72, etc) to be different from model to model. I would have thought (pure conjecture) that an L78 was an L78 regardless of the car it was dropped into. (manifolds aside for clearance reasons). I wonder why they would not call it a different "L" number if it were different internally.

So maybe a better example of my curiosity is whether the 69 L72 differed internally when the application was a Corvette, Impala, COPO Chevelle, or COPO Camaro. I sure thought they were the same, and assumed other motors would have been the same, too. Same curiosity would hold for other motors that shared "L" numbers, and were available across different applications.

[olredalert]

------Gary,,,For starters, a Z16 would have had a hydraulic cam and lifters. As a matter of fact the Z16 engine was the only square-port engine ever built for a specific option without a solid-lifter cam........Bill S

[66 L78 ragtop]

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------Gary,,,For starters, a Z16 would have had a hydraulic cam and lifters. As a matter of fact the Z16 engine was the only square-port engine ever built for a specific option without a solid-lifter cam........Bill S

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Unreal, here is some information that I hope you find helpful. Anyhow, if you have further questions, just send me a PM. Our discussion should probably take place at another location...

An RPO, such as RPO L78, designated a particular block, crankshaft , intake and cylinder head combo for a particular year.

Given the same RPO, the same model and the same year, the engine block stamp codes differed as a function of specific trans, carb and cylinder head combos.

So going back to your statement, you are correct in your understanding that an L78 is an L78 regardless of the car it was dropped into; the caveat being as long as you are comparing L78 engines from the same year. As you know, L78 engines are different and unique to their specific year of production.

The 396 in the 65 Z16 was RPO L37. The 396 in the 65 Vette was RPO L78. They were different in that they sported different cams, carbs and distributors. The cam on the Corvette was mechanical vs that of the Z16 which was hydraulic.

So addressing your inquiry regarding 1969 L72:

In 1969, the L72 was not available in the Corvette. Remember, the general rule of thumb is that the Vette always maintained its own unique set of RPOs. This was GMs way of maintaining the Corvette’s flagship status. The exception to this rule was the big Impala which borrowed the Vette’s big block engine in 1965 and 1966. GM likely felt this was acceptable because the huge Impala was a far cry from a threat to the sales of the Corvette. They were two different animals.

The only time the Vette and Camaro shared the same engine during the same year was when they were both chosen as the recipient vehicles for the aluminum ZL1 engine.

Anyhow, the COPO Camaros and COPO Chevelles were bare bone cars that came with the same crankshaft, heads, pistons, intake, and midyear 4 bolt engine block, cast number 3963512 that was designated for the special high performance passenger car.

The 1969 COPO cars essentially sported the passenger cars special high performance 427/L72. Just like when the Camaro was chosen as one of the recipient vehicles for the aluminum ZL1 engine, it again’ along with the Chevelle was chosen as the recipient of the passenger cars special high performance 427. The union of the lighter bare bones, Camaro and Chevelle with the omnipotent passenger car’s L72 was achieved via a central office production order (COPO). GM likely allowed the limited production of these COPO cars as they were designated for the drag strip as opposed to the Corvette which was heralded as the all American sports car vs drag car. Nonetheless, the COPO Camaro had the potential to compete with Vette sales so its production was closely regulated by GM.

Anyhow, I hope this helps

[camarojoe]

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The only time the Vette and Camaro shared the same engine during the same year was when they were both chosen as the recipient vehicles for the aluminum ZL1 engine.



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What about the 1970 LT-1?

[66 L78 ragtop]

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The only time the Vette and Camaro shared the same engine during the same year was when they were both chosen as the recipient vehicles for the aluminum ZL1 engine.



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What about the 1970 LT-1?

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Take a quick glance at the text, you will see that the premise of the discussion is 1969 (and earlier).

So if we extend the discussion to include the 1970 model year, then your statement would hold true.