Should have asked my question here. Hood clearance.

Obviously the wing nut is your biggest problem. I glued a piece of foam on the underside of the hood to press down on the lid in one application instead of using a wing-nut. But you also have to take engine movement into consideration. Engine will move on the mounts, especially under load, even if they are new and in good shape. Yes, you can fine-tune the clearance using different filter heights as well as different drop bases, as long as it doesn't choke off the airflow within the filter, between the base & top, or interfere with the throttle linkage travel.

What's the drop on the base now?