1. Open element air cleaners are 1950's technology. It's been widely-known since the mid-'60s that ambient (cool-, cold-) air ducted air cleaners make more power and have the potential to reduce detonation.

2. There's a huge number of aftermarket air cleaners that are a disaster for air flow into the carb due to carelessly-designed bases and covers.

3. Every half-assed speed shop on Earth is selling open-element air cleaners because they're cheap 'n' easy and profitable.
https://www.summitracing.com/search/...=air%20cleaner

 

Get a drop base for clearance purposes if you must go to open base. aaaaaaaaa

 

Check this out, may be helpful.

https://www.onallcylinders.com/2013/...r-size-engine/