Throttlebody

Oh, I used a sanding disk and an abrasive wheel to remove the casting marks first.
The material is rather porous so polishing can only go so far. 
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As for the external lip, doesn't that help keep the MAF hose secured?? That part of the housing is covered up by the hose once installed so I'd rather have that lip there to assure a good secure fit and no chance of unfiltered air sneaking behind the MAF. It would likely never happen though as the MAF is pretty much in compression between the airlid and the throttlebody.
Did you have any luck getting the casting pits out? That's kind of the luck of the draw. I had a CME that was pitted and SLP sent me a new one. The 2nd one was much better and I ended up having it chromed. I'll link a picture to it, but I have to go to my PC.







