Yep, that's my solution, too...consider S-100's Engine Brightener. It is an amazing product that really works. Turns the engine cases back to the original color. Use it after a good cleaning job and/or the engine is just looking a little faded. Can spray it on the fins as well.
If the silver tips are bare aluminum you will have to polish them back with Mothers or Semi-Chrome. You will have to do it very carefully because you do not want to get any more than necessary on the black part. One of the reasons I don't like silver and black engines....I'm lazy. After you are done spray a liberal amount of Pig Spit on it and it should help reduce the natural oxidation that al you mini um is so well known for.what about the silver tips of the cooling fins, thats where i'm having the oxidation problems?