Careful w/ the Belangers, I have them. They get so hot (1600 deg f+) they will melt your 02 sensors regardless of how much insulation you surround the o2 sensors with. That means you will throw codes, and go into limp mode, which means your car will sound great , but run like sh*t. You can solve this by using o2 simulators that Roe Racing sells ($149.00 or so).
Now, when u get your o2 sensors, make sure the wiring is not reversed in your sims (from stock)...or you will continue to throw codes. Several o2 sims come with the wiring reversed for some reason.
Also, the Belangers are so hot that if you have an oil leak you will probably have an engine fire (like I did), so make sure you keep a fire extinguisher in your Viper (Roe Racing sells them). They bolt right under the passenger seat. If you are going to track your car, get the comp oil pan, that will reduce the likelihood of engine failure resulting in oil leakage...with could result in a fire that could total your Viper. Final GTS sells comp coupe oil pans, and he is is a really smart guy.
Belangers are by far the best headers to me, however the claim of 40 more hp in some ads is complete bs. The stock Viper headers are actually very good and have just about maxed the hp.
Belangers produce an awesome sounding Viper!