I am in conversation with Classic Alfa regarding their water pump kit. At this point, it's a bit short of specifics. I am told that their bearing has "higher quality stainless steel", and is "truly sealed for life". I have not gotten an answer as to whether the use of their kit requires machining of the the block or timing cover.
I personally dislike "sealed for life" bearings. This is what is used in the distributor drive and distributor, and they wear out. Ball and roller bearings that operate in a spray of fresh oil tend to last a very long time, although I can see how the intermediary gear assembly somewhat masks the bearings from receiving said spray. I have drilled the front hole that allows drain oil from the Spica to enter the front bearing bore, and thence to the bearing. The rear bearing, history tells us, does not suffer quite so much.
I may order one of their kits to take a look and give it a try, but have doubts about magic in a bottle.
The bearing stack on the engine I'm rebuilding was something of a mess. Not sure I have all of the right parts or in the right order. Awaiting some stuff to confirm, but I may open up the second engine to compare.
Edgar - you might take a look at my Monty thread to see how to remove the inner race from the intermediary gear shaft.