Following up for posterity- Unfortunately, now that I'm back with the car and able to take measurements, the UNI filters don't come in a size small enough for these carb air chambers. At least the filters I was able to find. The smallest UNI sells are 5" OD (and very tall although that's a good thing because you could cut in half and you'd have your 2 filters), meanwhile my chamber is 4" OD.