I have a finished building my 489ci BBC engine in November of last year. I covered and sealed it the best I could, but when removing the coverings last weekend I discovered some of my instake had started turning yellow.

Are there any good, recommended products for removing this yellow/brown oxidation from cast aluminum? Should I removed the intake and polish it so it is easier to take care of? Any suggestions are appreciated.

Try some denatured alcohol. It works great to remove stains on cast aluminum manifolds, and makes them look new again. It's cheap, and any hardware store should have some.I don't know if it will remove the oxidation, if that is what it is, but it's worth a try. Stay away from oven cleaners, thay will stain it worse in the long run.