The KA24E from the 240sx but not the later KA24DE as they were the internal style pump.
The KA24E or KA24DE from the D21 Hardbody all had the external oil pump.
Yes the L28 turbo automatics had something similar but they are hard to find. Pull one for free from an old Hardbody KA, bang done.
My high mileage L20B had a hot idle oil pressure of 17 PSI. With no other change than a KA pump the hot idle oil pressure jumped to 29. That's a 70% increase at idle and the pressure is faster rising as it revs up.
It's high volume, so same number of turns gives more volume, so pressure goes up faster than the oil can bleed past all the bearings. It does not have higher pressure overall. They are still set for about 55 PSI. It just gets there quicker.
There is no way to tell from the outside. You have to remove and look into the inlet port. In the above picture of a KA high volume pump you can easily see the top edge of the rotor.
You can easily see that this rotor in a regular everyday garden variety L or Z series oil pump is shorter and sits well down in the pump case.
Below is the comparison between the regular and the KA oil pump rotors. The KA trochoid rotors are 13% longer
If you order one make damn sure you check and know what to look for. I bet there are more than a few out there that think they have a high volume pump but do not.
Hands down one of the cheapest easiest things for peace of mind.