[jocko]

I'd agree with Tim - more is better in a truck in most cases, but I think the real question for you is whether or not the heavier duty diffs are worth the work involved in changing them. It's not a terribly hard job, but then again, you're not getting a HUGE increase in strength either. For a street driven truck that you don't plan off-roading or towing a lot with, it might be overkill. Up to you if overkill is warranted. If you like doing the work and you MIGHT do some of the heavy duty activities, then it's probably a good idea. If not, I'd save the $ (even if it is a good deal) and spend those precious free hours doing something else to the truck. If you have lots of time and the parts are cheap and you enjoy that type of work, then go for it, it's all good at that point.