I have two. One original Z-28 and one from 15 years later. They are low for sure, and make a really nice entrance to the carburetor. But, the air filter assembly was very expensive, so bring plenty of coin. Don't know what just the base would cost.
Wow, I just looked them up. The entire assembly for $85 or the base for $60. I remember the dealer list as $145.00, and that was 20+ years ago.