I tried to find the same water pump pully, didn't turn up and March was so expensive I lost hope.
So, I run the smooth surface one. It is great. I used to jump belts at RPMs above 7500, now I can turn all the way up to 9000.
Note: I had to machine the water pump pully to fit my 1971 Boss 351 engine. I also had to turn the crank pully, but I am very happy with my current serpentine setup.
Hope this helps.
