Are the SUZUKI PAIR VALVE BLOCK OFF PLATES needed for the 08? I'll be running aftermarket full system, and air filter. Later I'll be getting the Weber BILLET CAMS, BOLT-IN.
No, not in my experience, they aren't.
I installed the Yosh 4-2-1 R-77 full system, and I am experiencing no popping on decel, or any other issue/problem with the fueling.
On the recommendation from HPC, I am not running a PC-III nor do I intend to. Neither have I done anything to the PAIR system. It is unobtrusive with regard to my bike usage, so there is no compelling reason for me to alter it.