Hugh makes a valid point only of replacing all four. Yet these days everyone is on a tight budget. And like anything else, "You get what you pay for!" That being said, I ask ALL my customers, how will they be using the vehicle? If you drive like my dad, then sure go buy some cheapies. They will be better than what you have certainly.
Again, it really depends on budget, and what your end goal is really. Before I buy just about any other non performance "branded" shock, I personally would put OEM units back in place before many other units. Again, the OEM units are for your truck. With many other "brands," fitment can be an issue. Meaning,a shock that might fit your vehicle, might also fit some sort of smaller or bigger, heavier vehicle. In turn, the shock you buy, might be too stiff, too soft or just right. Just like the porridge from the three bears. If I would use Rancho, then for MY needs, I really like the RSX9000's. I have used them for years, and have sold them as well.The Rancho 5000's are nothing more than a heavy duty shock for all around stiffness, but not too bad. They dont like alot of hard use. As the valving fades away rather quickly. I say, if you want to play with ride and handling plus make it fun, then the 9000's are a good fun shock to tune with. Plus, when customers purchase any high performance shock from me, wether its for street or off road, I offer to take them out for a one hour driver training session if they want. Yes, I build, prep cars, and also a professional driving coach. Good luck in your journey. We will support you what ever direction you travel my good man!
Dean, take a look at one of the toys in my library. Hope you like it! Ask me anything, anytime!:haveabeer: