It is amazing the number of different air cleaners that were used. When I removed the Edlebrock intake/carb combo from my car and installed the 68 Pontiac intake/Q-jet combo, the base was different. We went through stacks of air cleaner bases at my friend Mike's house before we found the one with a deep enough base that would allow the correct lid to be used. There are so many diffent bases it's unreal!