[Zeke]

Either send them out, bead blast them yourself or run some folded sandpaper between the fins and call it a day. You never see these things after the motor is assembled and in the car. You can coat them with a light coat of oil to keep them from rusting until first time you run the car. After that, it doesn't mater what you did before installing them.

At least that's the way it's been for me on the VW stuff I've done over the years.