Not sure if this is the right forum, but here it goes... (Mods move to engine section if needed)

I am in the process of replacing my injectors and intake gaskets (leaked at the rear). I took the intake, runners and plenum (TPI) to a machine shop to get cleaned. He said they boil it out (fine, whatever). Went to pick it up today and they are clean but also look the color of cast iron!?!? He said they boiled it in something at 350* then media blasted it, then washed it for $100. At the shop I used to work at (in CS), we put aluminum in a large cold vat of basically carb celaner and let soak, then wash it. He assured me there was no media left on/in the intake and running my hands over/in it this seems to be the case.

I'm not too concered about it, but it won't match the throttle body now or the plastic cover peice for the dist. Is there anything simple I can do to bring back the natural aluminum color? It just looks weird.

 

if you want pure uncoated aluminum an old trick it to use easy off oven cleaner.
DO TAKE IT OFF THE CARE BEFORE YOU CLEAN IT

DONT WARM IT UP FIRST.

spray it on, wait 20 minutes and white it off. wear gloves. big rubber ones.

i would almost bet that they pitted your aluminum and you are getting oxidation from what ever they used to clean it. maybe they even hit it with some fine grit sandblaster.
you are going to have to find out what they used, and then check on the net to see what will take it off. its not only outside - its inside too, and it can clog your injectors.

 

Do you have any pics? Pics would be great so "we" or "i" can determine the condition of the aluminum

 

Pictures... ignore the strut mount pics.

http://www.fototime.com/inv/80FD8773AACA632

click on the pics for the high res.

a before, in sunlight, without flash and with flash.

Looking at the closeup, that does look like pitting, I think it was a machine finish before, right?

 

What did they media blasted it with? anytime you have aluminum involved with heated chemicals it does weird things given that aluminum reacts with air to make its own oxide coating which protects the metal. . . submerging it in chemicals mixed with heat you now see where this is going. iv ran into this my self a few times. you can try a kitchen supple store they might have some type of aluminum cleaner. But i think your best beat is a air tool with a wire wheel there are different types of wheels fine and crouse wire. and you'll have to play around with speed to get your desired look - i have used this method on everything you may also want to use other types of hand abrasives. another idea as long as the pitting isn't to bad is to sand it down and polish everything. another thing would be to use a high temp primmer and paint on the parts. i also saw one of your runners was dented they sell a kit with ***** that fit in the tubes of your runner i forget where i saw this but it works from what i understand