I have a Delta faucet, not sure I can correctly identify which one. But it looks a lot like the Classic two-handle centerset lavatory faucet (model 2520LF-A). I downloaded the user's manual for that one. It identifies the stem unit assembly as RP25513.
My problem was a leak from the right (cold water) handle. I opened up both handles, and found a stem unit assembly inside each that looks just like the RP25513. In particular, each has a 1/4 turn stop, placed to achieve symmetric operation. The left handle turns 1/4 counterclockwise, from pointing left (outward) when off to pointing toward me when on; the right handle turned 1/4 clockwise, from pointing right (outward) when off to pointing towards me when on.
I bought an RP1740 as a replacement, and installed it in the right-hand side. I did not notice any degree of freedom in placement or orientation. Now the right handle points right (outward) when off, and rotates 1/2 turn counterclockwise --- the opposite direction from the original stem. I see it is documented to turn 1/2 instead of 1/4, and that is not really a problem for me. My problem is that it turns in the wrong direction. When I rotate it just 1/4 turn, the handle is pointing away from me instead of towards me. I want mirror symmetry, not 180 degree rotational symmetry, in my faucet. Worse, that 1/4 turn orientation does not really work, I have to remove part of the handle because the back wall is close.
No, I did not exchange the handles. Each handle is in the same side it was originally on.
Is there some adjustment I can make so that the right side handle points right (outward) when off and towards me when on?