why not carry the parts to a metal finishing shop and have them polished... those aluminum parts look beautiful when they're shiny... same thing done to wheels, valve cover, air cleaners, etc..
the shop are setup for it and price accordingly... i'm polishing my own parts: 3x2 intake; valve covers; rearend cover; small goodies; it takes a little time but the results are worth it and cheap too... i just do a little at the time when i feel like it; i built my own polisher with an old electric motor i had on hand and i use dremel or a drill for small crevices...
