You most likely will never have any issues as far as problems, and changing to lower gears isn't about avoiding any 'problems', it's about restoring the driveability and performance. Not changing gears is one of those adaptabily issues. Kinda like shocks and brakes; they never seem worn out because you adjust to any change (degradence) in performance as they wear and you adapt to it and accept it. You don't notice the lack of power and driveabilty because you don't know any better. However, I challenge you to search the forums and find someone that upgraded to lower gears and said "I couldn't really tell a difference at all". They're not out there. If you're truck is doing OK, then you may possibly have 3.73's; which is just that...OK. IMO, a gear change should be part of the budget for any (taller than stock) tire purchase if you want to retain the driveability and available power you once had...and it'd improve your fuel mileage.