Oooo... your gear's getting sloppy, but we should be able to get a workable adjustment for at least the short term. I don't know what that 7558 tool is, but the good news is we won't need it. All you need are sharp eyes (to read the balancer markings), a digital voltmeter and some hand tools for manually positioning the crankshaft. You never mentioned which engine you have, but I'm going to guess it's a 3.9 or 5.2 Magnum (multipoint injection). If you have a 5.9 engine, disregard everything I say from this point. The 5.9'er is a TBI engine and doesn't use a cam sensor.
What we're going to do is to position the crankshaft so that the V6 or V8 (depending on engine type) mark on the harmonic balancer is aligned with the TDC mark on the timing cover scale -- just like setting timing on an older engine, except we won't be using the easy-to-find slots cut in the balancer. You have to find the one that says V8 if you have a 5.2 engine. For confusion, there is also a V6 marking and since they're etched with a scalpel, they will appear very similar and can easily be mistaken for the other. Your adjustment will, of course, fail if the wrong marking is used. For reference, the V8 marking is very near a heavy-cut slot in the balancer, but the V6 scribe is way off by itself -- no mark near it. Once found, mark it with chalk or something to make it easier to see.
Rotate the engine by hand in the clockwise direction (as you stand in front of it) until the proper mark aligns with TDC. If you happen to go too far, back the engine up a quarter-turn and try it again. You want to stop with all your timing chain and gear slop trailing, not on the forward end. This will compensate somewhat for wear and tear on the entire timing drive system, including the (probably) worn drive gear and block bushing at the back end of the engine.
Now that the crank's set, we just need to adjust the distributor to the switch point of the cam sensor inside.
Locate the tan-yellow wire on your cam sensor pigtail and backprobe it with your digital voltmeter, set to 20 volts DC. Ground the black test lead and probe the connector with the red one.
Loosen the distributor hold-down (13mm) just enough so that the housing can be rotated by hand, but will stay put when you take your hand off and tighten it.
Turn the key on, being careful to avoid bumping the starter and messing up your earlier adjustment.
Now rotate the distributor clockwise a bit while watching your voltmeter. I like to shift the distributor to the right first and make the adjustment to the left because this would duplicate the operating relationship within the distributor as the shaft rotates clockwise. It keeps all slop on the trailing side of the distributor drive as well.
Now rotate the distributor counter-clockwise (left) and watch your cam sensor signal. If it was formerly reading 5 volts, stop when it switches to zero volts. Conversely, if it first read 0v, stop when it switches to 5v. Either one works. The instant signal voltage toggles, stop and lock it down. Once again, if you go too far or just think you could do better, roll the distributor far right and work your way back to the left. Absolute precision is great, but not essential because the operating range for cam-crank sync is ten degrees. I expect we can do much better than that, but that's the window we have to work with.
You'll notice that the ASD and fuel pump relays will fire momentarily as you reach the cam switch point, but it happens only once per key cycle. I no longer use the voltmeter for these adjustments, opting to just listen for the click-whirr of the relays and fuel pump. It's quicker and I don't have to probe any wires that way, but I thought I should tell you the recommended way to do it first.
If you happen to have the 5.9 throttle body injected engine, check to see if one of the two injectors firing in the throat of the throttle body skips a beat now and then. These injectors have historically had problems primarily on cold engines and since you have a pair of injectors, you can compare their actions to each other. They should look exactly the same, so if one skips a beat now and then -- or quits altogether -- it means that injector is bad. They're driven by the same timing signal, so there's no reason why one should work when the other doesn't.
Aaaand that's it. Lock that sucker down and let's see how it runs!