Re: Prop for Scott Atwater model 497

[frankr]

I "sort-of" went through the books. 5.5 and 7.5 take different props (diameter and pitch). That is not to say they won’t fit each other, but performance will probably suffer.
Prop shaft and prop were changed in 1952. So, 5hp Shift models through 1951 should be what you are looking for.
In 1953, the cone clutch was replaced with a rubber hub and different prop.
Just how much of this stuff can be interchanged, I just don’t know.