I don't think any G's came with the oval air cleaner. That was an over the counter part.
Small blocks got the regular air cleaner/snorkel, non Hertz big blocks had a snorkel that had a few extra knuckles in it to clear the finned running cat valve covers and the Hertz G's got the regular production '68 390 air cleaner snorkel since those G's did not get the finned aluminum valve covers.