One of the nice things about d
One of the nice things about doing your own major, engine-out service it that it gives you a baseline to start from...You know, 'cause you did it, what was done, without any doubts.
And speaking from experience, a few "extra" dollars now and time spent, is far better than trying to get to that (water pump), or whatever, after the engine is back in the car.
IMO, the water pump is a "must do", while the engine is out, unless you're 100% sure as to it's condition. Even though I had very few miles on my rebuilt pump, prior to the recent engine overhaul...I went though it again, only to find a hairline crack in the housing. Likely, this explaned the small dribble of antifreeze on the ground.
In addition, if the water pump impeller was not previously tightened enough, the impeller will wobble slightly on the pump shaft, damaging the back of the impeller. Although you might look at the damage and say...no big deal, and reassemble it, as this is not a sealing area...It is a big deal, as I found out. Any wear, or indentation on the backside of the impeller adversely affects the impeller to front pump housing clearance. This "extra" clearance reduces the efficiency of the water pump, resulting in higher engine temperatures. I had a custom spacer made...longer than the OE Ferrari one to reduce the pump front housing/impeller clearance...resulting in greater pumping efficiency.