Actually, they are for PCV. Designed originally for Corvette, and Mr Norm bought these, so he had no engineering costs. This air cleaner cleared the underhood braces on a A-body. Without any modifications, you can have PCV hose come from either side, and plug other side.
Incedently, when installed on a Mopar, the TriPower letters are backwards. These were designed for the Corvette, which had hoods that were hinged in the front, opened from the rear. When the hood was open, you couldnt see/read the letters standing in front of the Vette. That's why the offset wording on the Mopar 6 packs, sits backwards for the letters...