My old Zuk Sami fuel pump quit and I replaced it, but it has leaked at the gasket despite resealing it a couple of times when it should have easily have been sealed tight.

I'm talking ounces of oil, and not a few drops, either, and it runs down leaving a puddle under the car after shutdown. The old pump never leaked a single drop. I put dye in the oil and looked with a black light and found the stream coming down from the pump, and dripping off the bell housing (I originally feared a bad rear main seal).

I just re-pulled the new pump and it looks fine-no cracks in the casting or anything. Gasket looks like new.

I have another new one ready to go on, but wonder if there is a return oil passage for what oil runs down the pump activation rod that could be clogged that is building pressure behind the pump. I really don't see why the new one wouldn't leak like the last new one has been.

The engine only has a few hundred miles since a rebuild a few years back, and it is sludge/deposit free.

Anyone experience such a leak ever?

Are you sure it's the gasket?  Those pumps have an internal seal and a drain pipe (looks like it should have a hose), and if the internal seal fails they dribble oil from the drain.

I think I may have found the problem-

What I thought previously was a shallow casting flaw is likely a through-crack that dripped when I filled the lower bowl with brake cleaner fluid.

I installed the new pump. I may have just gotten a bad pump-
We'll see.