Something In my #5 Cylinder?
Ok, that plug in a Champion is an RC12YC and that's way too hot for any boost. And that extended tip is not good for boost.
I think to get your tune up under control and happy you need to run that plug when street driving and run an 8 in an NGK under boost, and maybe a 9 if the plug says it isn't happy.
And never an extended tip while beating on it.
Just my humble .02 and it's worth way less than you paid for it!!!