Here it is, the Car and Driver review of the ultimate ringer, in the form of a so-called 1964 Tempest GTO. 0-60 in 4.6 seconds? Sure! 1/4 mile in 13.1 @115mph? Why not?
C&D did acknowledge that their two testers were “Bobcats”, meaning a set of modifications to the engine by Royal Pontiac to optimize performance. But that wasn’t all of it. It is universally acknowledged that these cars had 421 SD engines to start with, as well as every HD component Pontiac could quickly slap a part number on, including a “NASCAR Suspension” and other such goodies. As a result, these tested cars were wickedly fast; almost certainly as fast or faster in many conditions than its namesake, the legendary Ferrari 250 GTO. And of course the lesson is that making a big splash in the media is much more important than truthfulness. DeLorean and Wenger were of course way ahead of their time.
Here’s a PDF (below) of the complete review from the March 1964 Car and Driver. Buckle your seat belts!