You need to ask yourselves how do you use your truck. I don't care what the label is on the outside, a shock is basically nothing more than a hydraulic pump. Both Fox 3.0"s and King 3.0"s are 3.0" diameter shocks, the big difference lies within. Inside of the Fox's there is a sleeve with by-pass ports which will obviously requires a smaller piston to fit. The King's aren't internal by-pass so it does have a larger piston. I saw earlier someone mentioned that all TT are running 4.5". This is a very true statement. But it's also important to mention these 4.5"s are external by-pass shocks with a fixed speed sensitive C/O useually attached to the same wheel so the tuning can be dialed in to almost near profection. Now take away the by-pass next to it and run the same section. The results will be dramatically different because you have taken away a key element, and that is the flexibility of tuning for all sections of the track, and not just one section. Without by-pass technology, it's very difficult to set up a shock that will fly through the whoops and still drive smooth in the smaller stuff.
Take Mictouch's work on the factory shocks. Since I last rode in his truck, he has since had about 20 revalves and port changes, and I can tell everyone reading this the truck was down right fast in the whoop section, and still road great on the graded roads. This was 100% because of his ability too not only change the valving of the stock shock, but also the ability to change the by-pass ports as well. This allowed him to focus on all aspects of the ride, and not just a small section. Now, give Mictouch a 3.0" internal by-pass and the results will be light years even beyond what he achieved with the OE shocks. When you have that much more tunability, you then have the ability to really play with spring rates, ride heights and many other factors because of by-pass technology leading to a shock that kills it in all environments. I can't even begin to tell you how sensitive the Fox 3.0's are to pre-load adjustments and piston position. It's also important to point out the quality of oil, the shape of the ports in the piston's ect...
I know in the world of cars and trucks, the old saying is there is no replacement for displacement. This off course holds true if all else is equall. I have personally seen a Mitsubishi Evo, Subi STi and other turbo cars run rings around big displacement cars. If it wasn't for the ability to tune the hell out of them, they never would have stood a chance. I've never been one of those my stick is bigger than yours. I don't care if the shock has the diameter of a pencil, if it works better, than I will run it. For those who do measure the smile on their face based of size, then the answer is simple, pull out the sleeve of your 3.0" internall by-pass and put a larger piston in it. Just keep in mind, you have tossed out the window the ability to really fine tune the shock for all surfaces.
One last thing. All of the major shocks are fully rebuildable.
