Thanks for the replies.
Mike - I'm still perusing the search thread - there's some good info there. (how come I can never get good threads like this when I search? What search criteria did you use?)
Larry - I know I don't have to replace it, but the car's 17 years old, I have no significant history on the car, and my experience tells me that even though the pump could last another 120k miles, it could also last only another 120 mi. I'd rather have the peace of mind of knowing there's a new pump in there when I'm 500 miles from home and 100 miles from the nearest repair facility when I'm on one of the 14 hr. Monte Carlo style rallies my wife and I like to take the car on a few times a year. These are often run at night, on deserted back roads (and someitmes desert roads, as in Death Valley), often at speeds in the vicinity of 100 mph, and I'd hate being stuck at 3am in the middle of nowhere with steam pouring out from under my hood! So, each time I find something wrong I fix it as soon as I can, as well as anything that appears like it could fail soon. Just seems like cheap insurance in the long run.
In regards to the transverse pipe coming off the side of the pump, all the parts sources appear to indicate that the pipe needs to be updated to fit the new pump. It does appear that the newer pipe attaches to the pump with a 6mm bolt through a flange, where the old pipe was just a slip fit with an O-ring. Are the diameter of the old and new pipe the same where it fits into the pump?