what you need to do is just go an buy like 15 cans of the cheapest degreaser you can find. You can get stuff from Repco that goes by the brand motortech, comes in a red aerosol can, that shit is the best stuff ive ever used, and its like, 2.20 a can, sometimes they come on sale, 6 for 10 bucks.
Just spray it on and leave it for like, 15 mins, then hit it with a pressure hose.
Make sure you protect all important electrical stuff, wrap a plastic bag around the distributor, etc
Applied Chemicals have an aluminum etch formulation, No666 from memory.
It will etch your alloy & leave it physically & chemically clean.
Just brush it on, leave for a few minutes, then hose off.
It will oxidize again within hours, & look similar to when you started in a few days, so good paint application very soon after it is dry is necessary.
It is the aluminun oxide on the surface of the alloy that prevents further corrosion of your alloy, so best not to touch, unless you plan to paint the thing.
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