All I know Is the 70s Dusters, prolly some others, are right bout 1.5"/1.25" Offset from CL... I laid out Everything last year with a tape and laser, using references, to build a custom fresh air deal, as some others here have done.....Now, if I'd remember the EXACT number darn it! Think the offset Aircleaner was 1.5.... and maybe I turned it a Lil. Maybe the small block is off 1 1/4"? Completely off topic also. . My Bad
