Do I need the PSR-100 or the PSR-200 shaft seal for my Sta-Rite P2R-A5D pump? I bought the -100 from you recently, along with that copper heat sink thing (item #7 in the parts diagram). But when I took the pump apart there was no copper thing inside it. This makes me wonder if I really need the -200 shaft seal, as you show in the 5A diagram. Please advise. I don't want to put anything back together without the right parts. Thank you.