HK,
Dissimular metals are dissimular especially when it coes to
aluminum---but if you were to use stainless attaching hardware, and coat
the threads, and mounting area's with silicone, this would prevent any
electrolosis from occuring between the areas in question.

Even a bit of paint on the mounting area's  and threads of the bolts
would help----anything to isolate the two metals---

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Terry--
74 Campmobile- (Clementine)
85 GL- (Delilah)
86 BMW 325 ES- (Eva)