Mercury 75HP outboard impeller housing question

Hi everyone,



Just a quick bit of input if possible. I pulled the leg off my motor last week and was going to replace the impeller. I noticed that one of the 4 threads that secure the impeller cover was stripped. I was going to helicoil and replace the bolts with stainless.



I have heard that stainless and aluminum should not go together in this situation. Any recommendations appreciated,.



Thanks

Alan