The water pump on my 1956 420 tractor has failed. I was embarrassed by how much play had developed in the bearing, but in my defense, it made no sign it was going until yesterday. The ball bearings disintegrated. I pulled it apart today to see if it was in good enough shape to be rebuilt, and I noticed that the impeller vanes and the interior surface of the pump are tapered. If I put a straightedge across the surface of the housing, the diameter at the opening would not be even close to flush with the straightedge. I suspect that this might have been caused by the play in the bearing that allowed the shaft to rock, but I have no idea if that's the case, or if it's supposed to be that way. Based on the area that shows contact by the impeller, it looks like it may have been made that way, as it seems too even to have been caused by wear. If it's wear, then I'll need to replace the pump because there would be no easy fix to the housing.
Could anyone who has rebuilt one of these tell me if these pumps are made with this taper? Does anyone have any experience with the aftermarket (I expect Chinese) water pumps for these, in case I need one?