Are you planning on powdercoating when done or polishing the aluminum? If you are going to coat them, I would sandblast them. I've blasted and coated a lot of aluminum wheels, compressor housings, and various aluminum pieces. Never had an issue. You just have to be careful to not blast on one spot too long. Chrome really isn't that hard to blast off. The nickel under it is what's hard.
Sent from my DROID RAZR HD using Tapatalk