Alum intake corrosion ( prevention)

You do NOT want to use powder coat on any surface that is internal to the engine or cooling system.

If the corrosion you're worried about is in the cooling system, replace your coolant, or it's additives, every two years, and get the magnesium sacrificial anode, which does NOT need to be grounded. Galvanic corrosion is about preference, not connection. If there is a more readily available source of electrons in the system, that's where they're going to come from.

If you're worried about the exterior of the aluminum parts, oil them, paint them, or powder them with the caveat noted above. This is called barrier protection. Like condoms.

Anodizing works but is expensive if done properly on something that large, and DEFINITELY hard to do on something that large if you're at home. And it seems to not do so well underhood, long term.