I'm not up to speed on Buick V-6 water pumps. On the last GM V-8 engine that I built, I used a pump from NAPA that had a round disk attached to the impeller much like the Flo-Cooler pumps. It is supposed to increase the pumps flow & cooling ability.
There are plenty of places to get a stock water pump,lots of the venders here. Also i believe there are a couple aftermarket, one from BeKool seems to come to mind supposed to lower temps significantly. Do a search
The Buick water pumps sold by most auto parts stores are generic ones, and will work fine in a GN.
But there is one pump made specifically for turbo Buicks by TA Performance which does provide more flow than stock pumps. The casting is a priority design as is the impeller.
This design is an off-shoot from the Buick V-8 pump TA built years ago which was needed for the extra heat that is generated for high HP builds and competition where cool-down between rounds is important.
The V-6 pump was evaluated and tested by Ken D. when dyno testing of high HP built V-6 engines, and it showed improved cooling as compared to a stock water pump.
There was a significant drop in temps around the combustion chamber area which is very desirable especially for all-out performance builds.
thanks guys for helping me make my choice .its just been awhile since I bought one just wanted to get something better than the one I would get at my local autozone or advance auto .thanks again putting my front cover together and that's the last peace I need to complete .
Flow Kooler high flow water pump. Made in the USA. It's a bolt in upgrade, with no mods needed. You should go to their website, it's highly educational in regards to the science of cooling and components.