C10 OEM 2wd dog dish cap types

[Voodstoc]

Forgive me if this is covered, I couldn't find what I am looking for using the search function.

I have been buying replacement dog dish caps on ebay (and getting a good deal) for my 70 C10. My OG caps are smashed, so I bought two and they were quite a bit taller, that is to say they extend away from the wheel more. I bought another pair and they are lower, closer to the wheel. I'm thinking that the taller caps might be 3/4 tons caps? Here is a pic of the taller caps:https://www.instagram.com/p/BN-b3QGgD3E/

This is driving me nuts, because I like the taller caps much more and I want to get two more to match without buying the lower ones by mistake.

Does anyone have a clue what the difference is? Thanks in advance.
~J