I've seen many a Z-28, Ran quarters against 'em, more than a few times, at five bucks a gear. But, I didn't see all of them. Out of the factory, with dual quads? 780 cfm was pretty much maxing out the performance. Throwing more gas, may have made them balk. Whether dual quads made sense or not ... they may have been an option ... Added to the "cool factor".