Best blasting media for aluminum?

[Rhino]

I have quite a few aluminum pieces that I'm looking to clean up before install (engine block / pan, accessory brackets, control arms, etc..) and trying to find something that won't profile the metal too much. Today I tried some 80 grit black diamond, but even at low pressure I feel it's too harsh. Unfortunately it's the least aggressive media I've been able to find locally. Anyone else have any success blasting aluminum?