The difference is probably in the base of the air cleaner, allowing the BB AC to sit down lower around the carburetor since the BB engine is larger/taller...
Umm, might be correct Gary but I was thinking it was angle/dimensions of bottom tube for hose to valve cover but never checked ours to determine what differences are.
I'm not saying I know the answer but, I did save a post about the differences in the original bases of the cowl induction air cleaners which I re-read recently. It said that the flat bottomed bases were the originals as opposed to ones with ridges which were repro or for Chevelle and the bend in the pipe that went to the valve cover that had two 45's, possibly were for the ZL1's to clear the rear pump of the double pumper carbs. Otherwise it was a 90.
But it makes me ask now, Is there a way to tell if the open element cleaner tops or bottoms in this discussion are original or repop?
BTW, I have an original lid with the straight stencil. Unfortunateley I bought it off E-bay and don't know for sure what it came from. It was said to be 68Z but there is no proof.
Now