The LM was originally an LSx F-body cat-back.
The "mufflers" are just empty bullets. Hollow.
I have yet to hear the Stang LM, but they sound like @$$ on a GM.
Especially with an ORP.
Most folks had to replace the "resonator" with a Dynomax Race Bullet
when they went with an ORP, just to calm things a bit.
I just made made my own LM, of sorts, by using the Dynomax bullet
right from the get go, and saving several hundred bux on buying a
complete cat-back. The race bullets flow same as open pipe, and they
actually have a bit of sound dampening ceramic packing. So for 40 bux
each, replace your muffs and get better results.
My .02
Dave