Hi Tim,
Good new, I found out which car the photo of the G. Pence air filter base came from, this is a Boss 302 (non Ram Air) air filter base. Bad new it's very difficult to find one.
There is also the 428 cj (non Ram air) air filter base with 2 smalls differences with the 302 boss:
- the crankcase ventilation in the front: plastic on 302 boss and steel on 428 cj
- I do not see a hole for connect the vapor fuel gas hose (from canister assy) on 428 cj ?.
There are reproduction of the 428 Cj but, i didn't find any for the 302 boss, but the modifications seem easy to achieve.
Nota: both Boss 302 and 428 Cj engine were equiped with 4150 Holley.