I thought Texas had a law indicating you can't run a car without mufflers. Of course with the side pipes installed you still technically HAVE mufflers- but a lot of the exhaust is just routed around it.

Also (perhaps a stupid question), do the Boss pipes bypass the cats- or are they behind the cats? Reason for question is if they are before the cats what happens if they decide to check the emissions at the side pipes?

I know I'm going to end up getting the Boss pipes- soon. I'll probably install the restrictors- but drill them out to 5/8". They sound just so perfect, IMO.

BTW, in a discussion of this on another site, I saw where Ford Racing did dyno testing on the Boss quad system and- with the restrictor plates removed- the HP difference was +6 to +7 hp. Not much, but considering the Ford Racing tune supposedly adds +16hp, that would be 420+16+7= 443 (awfully close to that 444hp number for the stock Boss 302 :^).

They exit the midpipe after the H crossover, so after the cats.

As far as laws for mufflers, some places enforce noise ordinances more than others, but a lot of people in Texas run muffler deletes/straight pipes.

Also, the typical drive thru type inspection place doesn't have lifts, so on a Mustang, they won't make the effort to visually inspect the exhaust system for the retention of cats. As long as your tune is okay, pretty sure you will pass the tail pipe sniffer.