I HAVE A LLY W 4,500 MILES, EDGE, NO CAT, NO MUFFLER, 4 INCH FROM CAB BACK. NEED MORE POWER. WHAT CHIP COULD I STACK W EDGE? SHOULD I GET A REAL EXHAUST? MAYBEE 5INCH? WHAT WORKS THE BEST? BIGGER INJECTORS? MY BUDDY HAS LB7 STACKED, WORKS ME PRETTY GOOD.