The Supercar Registry - 68 z/28 302 question

Among the very interesting Chevrolet engineering letters that were sent around for the Z was one from June of 1967 where a service pack engine was stated to be capable of 448hp under test conditions. In the letter it stated that the engine would produce closer to an estimated 403hp in full vehicle trim. This engine was decked out pretty well and had some notable work done to it and parts added like cowl plenum, headers, transistor ignition, etc. I would say based on that the numbers even for a 302 built back in the day was capable of some real good numbers but it is unlikely this one did unless it had some major work done either at the dealer or after. Depending on the cam the dealer added with the parts you are mentioning and with some other work it just may have produced those kinds of numbers. If the work done is more modern then who knows what it is capable of, if you have the money and knowledge you can build some pretty wild stuff. Gerry though I am sure has a plethora of knowledge including the insider tricks on the 68 Z's as others have noted having owned, raced and researched them for a long time.

Is the car a crossram car?

06/05/67 Z28 Service Pack Engineering Letter