LNB: SL3PIG-Z vs SL3PIG-P

You should be able to replace one with the other, there isn’t any difference. Both are legacy non-SWM 4 output LNBs.

As a note, without a SWM (SWM8, SWM16) multiswitch, they are not compatible with newer receivers like the Genie receivers or H25. Just thought I’d mention since you may be better off getting a SWM LNB since it is compatible with newer equipment and only requires one cable to each receiver. 

What are the model of boxes you have? Just to be sure they aren't so old they are legacy as well.

The box is a H24-100. Just came across this SL3K4NR2-01 LNB. Looks very similar to the SL3PIG-Z that I have, and it says it is compatible with all Slimline dishes. Is it safe to assume if it claims it's compatible with all Slimline dishes, it should work with my DirecTV Slimline dish and H24-100 or are there specific LNB models I should avoid?

Also, can anyone explain the differences in these LNB model numbers and what I should look for when comparing? There doesn't seem to be much info in this area when searching the internet or I'm just looking in the wrong palces.

If you replace a legacy 4 coax output LNB with a SWM LNB one coax output you will need a 21v power inserter to power it.

Shannon02, thanks for the reply, though I'm aware that if I use a SWM LNB I will need a power inserter. I'm just trying to find a reasonably priced LNB like the one I have (SL3PIG-Z) which is a non SWM LNB. It seems every time I think I found one, they have a different model number though the LNBs look very similar and claim they are compatible with all Slimline dishes.

Model numbers don't matter all legacy 4 coax output LNBs will work.