It sounds like its just out of adjustment, but you know that all ready! Don't they just bolt in to the bellhousing using three mounting bolts and no adjustment shims? You need to move it away from the gear so can you take a round file and slot two of the holes so it pivots away from the gear? It won't take much, twenty or thirty thousands should do it. You might want to talk with a starter rebuild shop instead of the local parts house, they may have a better idea on what to do for it.

In case you didn't know, there are three starter types for the Chevrolet 230/250/292. First type is a three bolt, bell housing type like yours, the next is a two bolt engine block mount with staggered bolt holes, and the third is a engine block mount with bolts straight across, or in line. The last two types are just the same as a V8. I don't know enough about them to know if you can convert one or not. There are two different starter ring gears, one has 168 teeth and the other 128 teeth and they to are the same as a V8 and will interchange.
Joe

1937 Chevrolet Inline-powered Streetrod