I have that one, but there is another one I am looking for and I may have the magazine title wrong, old age does things to the memory. Back in 1969 I had a Z28 that I was setting up for autocrossing and SCCA A sedan'. I had A friend who was a Trans Am owner/ driver who suggested that I contact Chevrolet Engineering for info. At the time the corporate ban on racing was still on. GM sent me two leaflets/articles. One was setting up the chassis for racing and the other was building the 302 for racing.
A few months later, so would have been mid to late 69 an article appeared in print titled "501 HP from 302 Chevrolet using stock parts" and author was Smokey Yunick. a couple months later another article appeared and it was setting up the Camaro Chassis for racing and authored by Dick Gulstrand, the GM chassis guru at the time. order may also be wrong as don't remember which came first. Both articles were word for word what GM Engineering had sent me a few months earlier. At the time I still had the GM version to compare and looked really familiar when I read the Mag article.
In the day "Sports Car Graphic", "Car Life", "Popular Hot Rodding" and "Hot Rod" were all giving the Z28 lots of press. I think it was Car life, but might have been Sports Car Graphic was running a series on building the Z28 into an autocross car. It stopped production right in the middle of the series and they were still getting killed in the Local LA autocross competitions. They had just got a set of Firestone racing tires, the at the time popular 1010 tire, but ceased production before had any results. I had already tried that tire and it was to small, went with the bigger Goodyesr tire designed for the Trans Am series and it worked great
