I can't speak from experience Rick, and as I mentioned earlier I've never been pro additives. These products have been around for a good while and are intended for
commercial engines,racing and street rods. They are produced and distributed by reputable companies. There are cautions on the labels to keep off plated, polished,painted,powder coated, and magnesium surfaces. And of course the usual warnings about eyes,
swallowing, etc. I don't recall a mention of aluminum heads or even aluminum radiators. It does state it will not affect factory warranty. That's about all the info I can offer right now.
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