Paint won't be effecting the pulley. Paint weighs so little Rust would effect it more than the weight of paint would. I painted mine before I put it on haven't looked at it in awhile to see how it is holding up. I didn't put paint on where the grooves were but wished I had after seeing the one that came off. I am sure you will all like the smoothness after it is done.
Green 2000 SVT #1166
mods-K&N open air filter & Custom heat shield, Custom y pipe and 30 in resonator,DMD, arm rest heightened
http://www.geocities.com/savinoss/Cars.html other cars-89 sable 197000 miles and still going-Wifes car 99 Mystique V6 5 spd