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

[66 L78 ragtop]

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Was it simply a sticker change? I thought the L78 Corvette was exatly the same as the L78 Chevelle, but with free flowing Corvette-only manifolds. (plus it was a Corvete, so of course it could have higher HP.)

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The sticker was indeed changed but reflected a 425hp output rating at 6400rpm as opposed to the 375hp rating which was established at 5600rpm...The HP changes occurred as a "trickle down" effect after the feds imposed a weight to hp mandate on GMs flagship Corvette. As you stated, the corvette had to maintain its superior hp rating and therefore a decrease in the vette hp rating meant a decreased hp rating for everything else.

The L78 Vette and L78 Chevelle had similar engines but not identical. You are correct in that the exhaust manifolds were different...But in additon, the pistons, the cams, the heads, the intakes, the carbs, and distributors were different as well.

The 65 vette L78 and 66 Chevelle L78 sported the same 4 bolt block, the same bore and the same steel forged crank...