Okay here's the lowdown....
While I was waiting for my other Muff to come in , I got my hands on a Harley Fatboy factory slip on .... so I decided to mount it on the bike ... And yes it was a pain in the ass . This one has the hi flo catalytic and the baffle is still inside ...
I wasn't expecting much because the Screaming Eagle failed me .
So I started it up and it sounded really good .... I took it for a blast and I don't know happen but it actually was picking up in speed and it sounded quite loud almost too loud .
The bike even shifted gears better ... extremely strange

The only thing is that it did is lag or slight hesitation in first and second gear untill the revs kicked in and then it would pick up and go .
I did get a fair amount of decel pop , but I did find a leak from header to muffler .
I have the fuel mix screw turned 1.5 turns counterclockwise
I have to test tomorrow maybe I have to turn the screw back a little bit more I just don't know exactly why the lag is happening .... any help from anybody ... I know it could be a little bit possible from the little air leak

I am actually extremely happy with this muffler