Let me know if you find a "over the counter" filter for it. I have cut a real 6-pack filter and modified it to fit. Had a few sugestions about trying a large round filter and "molding" it to fit the oval shape of the air cleaner assembly. Right now I ordered a Ford 427 390 FE tri-power dual quad oval air filter that's close, but won't know till it comes in for sure or not. Will post the number if it works.
It supposed to be about 20 3/4 inches long, 9 1/2 inches wide 1 1/4 inches thick and 1 3/4 inches tall. I know its a bit small but might be able to shape it once I get it in my hands. Also was told to go to parts store and get product reasearch phone number, and call to give them dimetions and they can tell me the correct part number for it. Tried with K&N, and they said they had no filter that would work. Hmmm.....