If it has 100 plus hp then why does it only run a 4.9 ET? My thinking exactly.
The Pulse Charger pipe is the shit for 4 strokes but I have never heard of it for the Banshee.
I don't know what is going on over there. They used to never ban anyone without a shit load of warnings. If you have the YFZ450 owner's id over there I can get him in touch with you if you like.
If you are running stock a-arms you will most likely want to remove all the preload. No negative side effects. It will make it sit a little lower and absorb the small bumps at slower speeds better.
If you are interested I have a set of shocks off my YFZ450 for sale. Only a couple of dune rides on them. $165 shipped. They have the white springs on them also.
My CPI inframes fit fine with the cheetah cylinders. They do rub on the filters though but I just wrapped the stinger part of the pipe back by the filters with header wrap and I could still run outerwears.