What kind of finish do you want them to have?
Polished would mean a good de-greasing followed by sandpaper at 600 and then a 1000 grit. Follow that up with a good aluminum polish on a buffer and they will be shiny. It is also the most labor intensive method but you get good results. Here is a pic of a friend of mines 289 FURD that we cleaned up in the spring. These were in pretty bad shape and came out nice. Just tape them up and paint the centers after everything is polished. You can polish everything but man its a LOT of work to do three sides and the bottoms of all the fins.
