[vidman]

Just to put more gas on the fire, when i had my 504 on the dyno it was hooked up to a set of Magnaflow mufflers to make the runs.. (keep the noise down) We made 15 runs on the mags and 2 last runs with open headers. The magnaflows robbed 12hp and 21ft lbs off the peak numbers. He also had flowmaster 40s set up to run also but he said that they rob more power than the magnaflows. I,m going to run Spintech super-pro 9000s on my ride when its complete. I wish i had known that he ran the different mufflers to prove to all his buddies which ones are better, I would have set up some spintechs to try out just to see what those numbers were but i quess we will never know for sure...