These mufflers have been on my truck for about 1500 miles. Model #4331. Not sure about the performance gains, but I remember STANK saw some hp & tq gains with a similar set of SpinTech mufflers. Removing them for a set of Dynomax Race Bullet mufflers for more sound. They cost me about $90 a peice, I will accept $100 for the pair. I do accept paypal and actually prefer it. Make an offer I may take it.
Inlet Size: 2 1/2 Inch Center
Outlet Size: 2 1/2 Inch Center
Case Size: 4 x 6 x 12
chack them out at SpinTech
Inlet Size: 2 1/2 Inch Center
Outlet Size: 2 1/2 Inch Center
Case Size: 4 x 6 x 12
chack them out at SpinTech