Louvered resonator

[John A. Heer]

Long ago, Jon wrote:
Magnaflow XL Powerpack, part number 14457.  24" case, about the biggest
thing you can fit in a normal B-pipe.  Walker seems to have ducked out
of the resonator market, and Thrush models are either louvered or not
stainless.

Jon, are louvered resonators a bad thing?  I notice that Summit Racing
carries its own stainless resonators (tube mufflers) which have a
perforated louvered core (about $130 for 24-inch).  Would this achieve
the same purpose as the XL Powerpack?  I am having trouble finding
sources for the XL Powerpack.  Any comments?

John Heer
93 SE-R not stock