Mako
About the Mako Shark engine. It was originally scheduled to have a 396 and the air cleaner cover had chrome letters saying Mark IV 396 on it. By the time things were getting together the new, for '66 production, 427 was available so it was changed to a 427 before it's introduction to the public in August '65. It had many unique features including retractable bumpers and spoilers and digital speedometer, fuel guage and clock. Very high tech for the time.
In '69 it was returned to GM styling for a freshening up and some additional custom work. That was when the ZL1 engine was installed, plus the appearance changes we are familiar with. It was then reintroduced as the Manta Ray.
Tom