Rick ...What I ended up using is the 1969 Z28 and 1970 Chevelle with Cowl Induction. The base on these are 17" the same as the Dual Snorkel air cleaner. Problem is there are not enough owners of the latter to get any responses. I even tried Team Chevelle. Here is a couple pics you can use for reference. The Cowl Induction style has a Higher angle (35 to 40 degree) and seems to have the oval mounting hole open and there seems to be a notch taken out at the top.
