FRAM's vintage series was really nice, here's the CA305V that should be for your 340 4-barrel:

https://www.autozone.com/external-engine/air-filter/fram-air-filter-ca305v/376666_0

Unfortunately, those stopped being produced a few years ago.

The next option would be FRAM's CA305:

https://www.autozone.com/external-engine/air-filter/fram-air-filter-ca305/246459_824302_6156

Then there's other manufacturers.

Mike.