Should I replace the lifters in my Dodge Ram 1500?

I have a 2003 Dodge Ram 1500 and the lifters tap like crazy. It was tapping for a long time but now has become quite loud. The truck has nearly 160,000 miles and the bottom end sounds pretty strong. Should I replace the lifters or will it just keep on tapping? This is my only transportation and I am scared that it will throw a rod and I will have no more truck. HELP!!