I bought a set for a 383 then decided to go with 440. I had not installed the headers yet and i called my supplier and asked him. I was told that one of the sizes would work the others would not. I bought the 1 3/4" headers and I was told these will work with both the 383 and 440.

good luck

1969 Road Runner Bench seat, four speed 1999 Dodge Ram 1500 http://picasaweb.google.com/moeville