Now that I have decided to purchase a 2009 3670, I have ordered a new 2012 F350 Crew, 4WD, 8' Bed, Diesel Tow Vehicle. I have gone back and forth re DRW vs SRW AND 355 Rear End Gear Ratio. The Truck is not going to be delivered for 4 weeks. Not too late to change something.So now that I have...