That body style of Chevelle ran for 2 production years, 1966 and 67. GotSmart pegged it via the taillights, it's a 67. Although the rear was mostly the same with the small fins at the rear corners only the 67 has the wrap around corner tail lights as in that picture. The 66 tail lights were inset in the back and did not wrap around. I had all manner of 64s myself.