Valve spring help.

I like thier product, but I too found the tech guys a little sad. I can read the catalog and website pages too. He finally had to go and pull one of each part number I gave him, so I could explain my question with visual aids. Then he said "yep, they do look very much a like." I knew thye looked alike. But would one fit where the other didnt was the question...The catalogs didnt say yeah or no...