This is at the 1967 Daytona 500, probably during practice. I have had several arguments over the years with people saying that in 1969 Ford was the first to use rear exit exhaust, and that they used successfully until NASCAR banned it. Well, a picture never lies. As you can plainly see the #43 Richard Petty Plymouth has rear exit exhaust. Talking to the gentleman who took this picture, I learned that Petty’s team tried it in practice and they didn’t notice a difference in power, so they went back to the side exit exhaust. The biggest benefit to rear exit exhaust is that if a car tried to draft them it would overheat, but some say it gave a slight horsepower increase as well.
Also a quick note from the writer: we apologize for the watermarks on these photos but often times these pictures get stolen and are sold on eBay. We feel we need to watermark them to protect them.