For true. I was at a Vintage road course race and there was a beautiful '68 Boss 302" Parnelli Jones clone. The Vintage guys don't really do engine tech, but this guy never raised the hood in the pits. He couldn't hide the fact when he was on the front straight, he pulled the legal SBF cars like they were roped to a post and that sound was unmistakable; once heard, never forgotten.
While wandering off-topic, at that same Vintage race was a '69/'70 big block Corvette with the side pipe headers. I first heard that sound at Le Mans in 1969 and it too is unique and immediately recognizable.