Here I am, tight budget and all.
Ok, first, get your pyro and boost gagues, with the t-couple in the rear half of the manifold flange just before the turbo. If memory serves, TST has a god pic of the install on their page
www.tstproducts.com . The pyro is next to useless in the exahsut pipe. BTDT. Up to a 450 deg difference on a stock truck with a gated housing. READ THE STICKIES first, so you will have an idea of what I'm talking about. This goes for everyone.
Valve adjustments, fuel filter, make sure air filter is good, get base line readings, and go from there. Maybe run a good dose of DIesel Kleen, StanadynePF et al, through the tank to clean stuff up a bit if you dont use them regularly. I'd assume that since it is to be used in your business, you will want to keep smoke to a minimum. Timing needs to be set to 1. 5-1. 6mm (. 055-. 060") @TDC. (I have the tools to do it, and can do it in exchange for the bed when you get the custom bed on there

) Much more than that, and you start to lose ground in MPGs, and perfromance, unless you have aftermarket injectors with higher pop pressures, (that will in effect retard the dynamic timing), in which case, you can go a little more. Make sure that who ever does the timing doesnt rely entirely on the timing pin for TDC; the pins have been known to be as much as 5 deg off one way or another, rendering the effort of setting timing a waste of effort. True TDC needs to be established before any timing measurements. There are several ways to do this, and I can make another post with some of the methods if needed.
Fritz's Ram Tech Page has some good ilustrations of what to turn where for the full power screw. I will warn you, if you turn in the power screw much more than 1/3-1/2 turn without tightening up the AFC spring tension, you WILL get smoke. At least I always have, but I sometimes wonder if I've ever had a stock truck.
Back the "smoke screw" (T-25 Torx and 12mm deepwell) on top of the AFC housing all the way out (ok, not ALL the way out, but far enough that the diaphragm is resting against the bottom of the top cover, not having the set screw pushing it down). This just determines where the tapered cone starts, and since you have zero boost, start out with minimal fuel to reduce smoke. Spring tension determines how fast the fuel comes on vs boost. CAREFUL OF THE POTMETAL AFC HOSE- it will snap if you breathe on it wrong. Still driveable, just feels like a PSD

:-laf Replacement was $55 from the dealer 4 years ago; $22 from CUmmins.
Now, back to the cone taper. Some have had good luck and little smoke by turning it to the max. I like to set mine at the 50-75% range. (or less than 50% and grind on it to get the top end back to full power) If you look at the cone, you will see the taper is offset, with the deeper side allowing more fuel flow. The deep side, for our purposes, is 100%, the shallow side is 0%. 50% is halfway between the two; 75% being a little deeper. GUide pin comes out from the front side of the well, and that is what rides on the tapered pin.
Start with the AFC "starwheel" (i'd like to know what drunk came up with that term, the thing looks like a 32-tooth gear) to about 5-7 turns up from the bottom. You may need some tough fingers to turn it. MOst of the trucks I've had already had that wheel botomed out. Fast response, but with the stock exhaust housing, makes some smoke.
Once you get the AFC set up, take it for a spin, see how you like it. If you need more, turn the full power screw in about 1/4 turn at a time, and see how it runs. It may take a few weeks to get it how you like it if you're as picky as I am. I have mine set to where it hardly smokes at under 20psi, then a light haze at 20-35. Unless I stomp on it at 3rd gear idle, in which case it will leave a blackish haze.
For a stoc truck with stock turbo, 1psi boost equals roughly 10HP. With the 18, I'd venture that's at the wheels. You should have 15-18psi peak at stock, (with the 18cm; take of 2psi for 21cm) 22-24 peak after my recommendations, and it comes on quicker. From your siganture, and with 3. 54 gears, you can expect 17-19MPG empty (<800# load, no trailer) aruond town, and 20 or so hwy, provided the pump and injectors are up to par.
Daniel