I tried a non-online game's header on an online game but was unable to connect. I believe headers should come from a game that is capable of going online. However, I only tried my Cubic Ninja header dump with SSB vs my Street Fighter IV header dump with SSB. Every game that I have that plays online has worked with my private Street Fighter IV header. I used Gateway Rom Patcher to fix the chip ID and manufacturer as necessary for each online game.