[Scully]

I've been wondering the same thing, I was thinking about running a different pump. The threads don't appear tapered but they also don't have an exact size, or at least a common one.

I took my calipers to the threads and they're ~15/16", 29/32" or 0.91" to be exact. In MM it's 23.3mm. I don't have any idea how they came up with that.

I have found one sketchy item on Scamazon that looks exactly like the inlet valve, I might order one. I might keep digging until someone else chimes in though.

 

[Scully]

Mine pushes water up about 6" to the top of my griggs, down a ~12" in the griggs, and then up 3' to the tank. It makes it, but it's not mind blowingly fast. It's more than a trickle but not anywhere near 100gph, maybe like 30gph. I am pushing it in my situation though, 3' is it's maximum head height. Still have some fiddling to see if I can't get some more flow from it.