Lots of COG Members have installed the Delk. Slip-on's and love them.
On the headers, fewer have installed them, but I've heard no complaints from those that did.
As far as I know, all did the 4 into 1 system. You may be the first to do a 4 into 2.
Ride safe, Ted
PS: On my bike I used Area P Slip-on's.