Stainless bolts in cast aluminum. Corrosive?

[Belrix]

One of my grease zerks got knocked out of the rocker arm assembly on my motorcycle. It's poor design, the fittings hang low like the teats on a sow and a pot-hole or a curb is perfect for snapping them out. I'm one of a several on the Kawasaki board who've had this happen. (Vulcan 900 Classic, by the way).

The cast aluminum is tapped for the fitting and the force of the impact snapped it off and even took away a little of the casting, too.

I replaced the fitting briefly, topped the grease off with my grease gun, and replaced the low hanging ones with stainless bolts & split ring washers from Ace Hardware.

Now that they're in, I'm worried about galvanic reactions or other corrosive actions that might make this a bad idea after all.

Any ideas if this is a good long-term solution?