..open air intake alone, requires more of a jet increase than the addition of an aftermarket exhaust alone...
...anytime you significantly increase air flow into the carb, with a free-flow filter in place of oem airbox, you must up-jet 10-15% in jet size!!
..given, the 4ts are a bit more forgiving, but blue..you gotta be running lean...
..of corse, i dunno how restrictive the shroud might be...