The old 6.2 filter was 33123, I think, the screw on type, but the cucv primary filter has a water drain at bottom as well. it is supposed to be drained regulary, esp if you are filling with cans or at an old farm tank. Try using it everyday if you suspect your fuel, a few drops will do. If water comes out, let it run till it is diesel. If there is no water you are ok. But if you think you have more than a pint of water in your tank, if it were me I,d hook up a pre primary, even temporarily, Racor filter, with a large visible water capacity. and after a while use a fuel dryer for the residue. The cucv tank is hard to drain , not like a heavy truck tank with a plug and a regular shape.