i am sure it sounds nice,but at stock levels, mufflers or catbacks dont gain much rwhp at all. maybe 2-3 if you are lucky. it will drop EGT down maybe 50 degrees. 4" full from the downpipe on is the only way to do it for significant increase on combos making 500 hp at the motor (or over 400 rwhp).

 

By far the highest HP snigle chip on the market is by Pacific Perfromance Engineering. The chip gives you 218hp and 380ft/lbs of torque and it also takes your top speed to 120mph and increases REV limit to 3700RPM. It is a duramaximizer chip with a Tech IV programmer to acheive this. The cost for this is $2,400

 

For you diesel shoppers, you might find this post interesting:

https://ls1tech.com/forums/showthread.php?t=162919

 

i was wondering who has the best price on the juice box for the duramax
thanks.. mr. duramax