The big block engines increased from 396 to 427 cubic inches in 1966. It was the last year for knock off wheels but the first for shoulder harnesses and headrests.
The 1966 Corvette was not eligible for the SCCA Trans Am, due to the upper limit of 5.0 liter on engine displacement. Chevy's only eligible car was the Corvair.
FIBERGLASS FACT: The most popular option in 1966 was the AM-FM radio
which was installed in 26,363 cars (95%) at a cost of $199.10 each.