Fuel tank installed

The lock ring that came with my SS tank from Van's worked fine. I tried a thicker lock ring on my old tank ( Mega Parts ) carries it, ramps are higher, could not even get it in. It might work on another brand steel tank, but not my old inconel steel tank. I tested mine for leakage before installing it in the car, also, they might not leak with a gallon or two, but would with 10 or 18 gallons of fuel weight .
What did you end up using for a sending unit/pick up?