I too like the sound of the flowmasters. Dual 2.5" pipes should sound nice. As for 14.0 in a 4X4 naturally aspirated, good luck. Not to sound critical or nothing, just that you have a huge amount of weight to get moving and you'll need a buttload of torque to get there in 14.0. Weight reduction will be your friend in your 14.0 goal. Take as much weight as you can off your truck when on the track. Some kind of ram air induction to help force more air into the intake at the track will help also. Be sure you richen up your fuel mixture quite a bit since you have descreened the MAF. Mine was waaaaaaaay lean after descreening the MAF and rattled like crazy.