New sending unit leaks at lock ring

Yeah, I still have it. I'll try the old ring, and if that doesn't work, I'll try bending the tabs.
It should work. I had this most aggravating scenario happen to me also, leaked like a sieve using new parts, put old lock ring back on and problem instantly solved. When you make the swap, look at the two rings together, very evident what the problem is. Sad the aftermarket cant manufacture this stuff correctly, especially considering they only have to copy it, not invent the concept.