I know this has posted to death but I have 2005 LLY GMC. The only mods are an edge juice and K&N filter and intake tube. I have heard changing the mouthpiece can be helpful and I have plans for an exhaust upgrade. So my question is What mouth piece to get and where to get it. What other mods should I do? Its an everyday driver and I pull a horse trailer and other trailers occasionaly. Thanks for helping a new guy out.
