Ford Small Block camshaft thrust plate (backside)

Ford Small Block camshaft thrust plate (front)
I'd like to talk about what I have here. Years ago, I disassembled a 1982 Mustang GT 5.0 H.O. engine. Now that I'm retired, I decided it's time to refurbish this engine, so I'm inventorying what parts I have. Unfortunately, I threw some other parts in the mix, and I'm not sure which plate is appropriate to use with my '82 block. Can any of you tell me anything about these cam thrust plates, such as why they are different shaped and what version engines they go to? Thanks in advance!!!