That Hib article is about a custom system. It looks like he only used the resonator from the Flowmaster cat-back system. One thing I found frustrating about his article was all the custom work done to fit that resonator into the LT4 system, yet there isn't a single picture that shows it!
FWIW, you can get the Flowmaster system from Summitracing for
under $600 new.
Also, FWIW, if you were going to have a shop install it, you could probably just have a shop replace your mufflers with Flowmaster mufflers. If you had a '93-95 then it would probably have a similar or better gain, plus you could keep the stock look with the rectangle tip. But if you want to do it yourself or you want to keep the stock system in-tact, or whatever, the Flowmaster is certainly a low-cost cat-back way to go.
I seem to recall reading on the listserv archives about the resonator not being very ideal inside, though I can't recall exactly.
Flowmaster generally has a very nice sound, though.
