air claener pie tin measurement ?

I have a 1972 motor home 440 air cleaner, it looks like the top space where a pie tin would go is 10 inches. over the years where there different measurements.

I just measured one. 10' center to center on the bevel. 10-3/8" outside lip to lip. I think they are all the same.

Should drop right in if you can find one.

Thank you that's the measurement I need. the research I have done they all look the same. I took 2 6 cly air cleaner bottoms cut the air snorkles off and put them on the 440 air cleaner made my own Dual air filter. My friend I got it off, it was the grand parents motor home. A 1979 he pulled the engine and trans for a project never used it. IT has a 727 trans with a short tail bolt on yoke. The Motor home, had 33k on it. The air cleaner has a INFO sticker on it with year 1972.