Here is the flowmaster y:
http://www.jegs.com/images/photos/30...9-Y214300A.jpg
or perhaps ramp it up to 3.5" all the way back:
http://www.jegs.com/images/photos/30...89-Y250350.jpg
I wish someone made an offroad down pipe/ypipe with a single 3.5" termination. =/