Welcome to the site Luis:
Okay first you need to consider the cause of the noise. Perhaps low oil, or a failing oil pump is not allowing the proper lubrication needed for those. However, knowing if it is a more severe problem would certainly help you answer this question. I would not immediately jump to rebuilding the motor if a simplier and more cost effective way can be accomplished. Now a few things, I assume the truck in your avitar is the truck in question, looks like a 2wd, is it a 4 cyl. as well, or does it have the 4.3l? Here are a few more questions for you to help narrow this down. When was the last service? Meaning oil change, plugs wires and so on....? Okay, now as for changing just the lifters, should you need to go that route, replacing the whole head would make more sense... and if that is the case, now we are talking about rebuilding the whole motor. The miliage is way to young I would think unless under severe stress to need a complete overhaul at this point. Just my thoughts here, check the oil level and condition of the oil first, then go from there.