I know, I know...another ticking thread...

A buddy of mine with the exact same model as my truck parked next to me the other day and we noticed a difference...his sounds a lot smoother than mine and there is a VERY noticable tick coming from under my engine towards the back that he doesn't have.... I've checked injector lines and nothing is loose...any other ideas? It almost sounds like the timing could be ever so slightly off, but the timing is electronic isn't it??