[William]

The Estes '68 Z/28 convertible was built July 1968 virtually at the end of '68 production.

Many of the parts Estes is alleged to have "approved" as a result were featured in the May 1968 Hot Rod magazine in an article titled "Just For Fun: 68 1/2 Chevys". In addition Car & Driver tested a cross-ram/JL8 '68 Z/28 in the July '68 issue. Magazine lead times are about 3 months so these events took place around March 1968, 4 months before the Z/28 convertible was built.

The K66 TI ignition had been a regular production option for years at that point; headers were optional on the '67 Z/28. Wayne's Guinn's Book "Camaro Untold Secrets" has all the info. Chevy had a JL8 engineering car by October '67; some cross-ram docs are dated August '67.

I cannot believe the BS surrounding this car.