Just digging around using Keith's part number, I see Summit has the correct V8 water pump going for $82.95. It's got the deep vanes and cast impellor. I think I'm going to order one and see how it goes. It sure would be nice if this solved my troubles. My car runs fine going down the road, but gets hot idling in traffic. I suppose grabbing one of those laser temp gauges might be useful too, to see if the temperature varies from left bank to right bank before making the swap. That would be a good indicator as to what pump is currently in the car. After reading these posts, if the left (driver's) side is hotter, then most likely, there's a short vane pump in there.
BigAquaBonney...Thanks for opening this can of worms and Keith, Thanks for helping put the lid back on! It's threads like this one that can really make a difference. I salute you both!
Link to the Summit pump...
http://www.summitracing.com/parts/AAZ-58-594/?rtype=10