When it comes to cams it's the overlap that is the biggest factor as to tailpipe emissions; to get a better idea you need to know the LSA of the cam as well as duration, that duration on a 108-degree LSA will certainly not pass emissions where on a 114-degree LSA it probably will, assuming the tune is dialed-in. Anther factor is whether the cam is right-sized for the crank stroke and displacement, a cam that is domesticated in a large stroker can become very rowdy in a 5.3L. FWIW of what I've read on the f & y body forums a 216/220 cam on a 114-degree LSA in a 5.7L-6.0L is the largest recommended to pass california emissions and will need a very good tune...

Mr. P.