The L36 (427/385 horse) was the standard powerplant. Painted orange with black air cleaner, except for the SS427. They got chrome valve covers and air cleaner lids. Also, the L72 was offered secretly for those who knew enough to ask and had a dealer who knew how to order it. The L72 was the hot Corvette 425 horse engine. Corvettes by that time still offered that motor, but with tri-power and a 435 horse rating. BTW, the L72 retained the Corvette exhaust manifolds when used on the big cars, and it used duals without the rear resonators (unlike the L36).