You may consider using some dielectric grease (silicone type- 3M makes great stuff) on the connection. It keeps corrosion down to a minimum and helps keep the connection good over time.

 

No consequence by bolting them together, on the F engine or the K engine.

 

Something to keep in mind is what is called a Ground Loop. When there are multiple grounds, and they aren't all grounded to same place electrically. In other words, there is significant resistance between one ground point and another.

So its a very legitimate question to ask. Thankfully these 2 points aren't creating such a loop. But definitely something you want to be careful about.