Not sure why you would even mention 3" full at this point. Not even close to the power level that is needed for 3" and will probably take a power loss due to lack of scavenging.I'm a big fan of bassani mid lengths bassani x pipe and bassani cat back if you're staying 2.5" and kooks 1 7/8" x 3" collector, 3" x pipe, and bassani 3" cat back for going full 3"