Lots of redundatnt information here, but thought I should compile all the tips and tricks I could think of in one spot.
If you don't have a service manual and a parts manual, that's the first place to start.
You will need the following special tools:
timing pin 3P-1544
pump gear puller 6V-4069
Maxwood 5146 46MM flat wrench cut or ground to fit the water sleeves
Every kind of "special" 9/16" wrench you can get your hands on. Get stubby, long, S-bend, offset box end, ratcheting, ratcheting stubby, flex head ratcheting, etc.
A slide hammer makes injector removal much easier.
Tips in random order:
As long as you lift the head straight off the block and set it down on something soft, you can leave the injectors in the head for this work. That said, I replaced all my injectors as they are really easy to replace while the heads are off and they are only 77 bucks each.
When you remove the rocker arm assembly, don't touch the two bolts at the ends of the rocker arm, they stay on the shaft and hold the assembly together when you lift it off the head.
Don't loosen the ring of bolts around the engine oil cooler case unless you intend to remove and rebuild it, something I do not recommend doing unless it's leaking.
Pay close attention to the correct bolt tightening sequence when putting the exhaust manifold system back together.
When you put the after coolers back together use a bunch of 1" 3/8"-16 bolts to seat the after cooler core in the housing WITHOUT the aluminum ring clamp. Once the core is seated, remove the 1" bolts and install the last gasket and O ring with the aluminum clamp ring and tighten it slowly and evenly with the original bolts and washers. That clamp ring is brittle and costs 460 bucks, don't ask how I know this...
Take a zillion close up pictures of everything before disassembly
Bag and label all the parts and fasteners.
A pair of 4.5" or 5" 3/8-16 bolts with the heads cut off can be used as studs to get and keep the exhaust manifolds and gaskets in place on the heads while you get a couple of the regular fasteners installed. Once the manifolds are secure, you can back the studs out and replace them with bolts
If your exhaust manifolds have rust around the bolt holes, one of these: https://www.harborfreight.com/53-amp-12-in-bandfile-belt-sander-62863.html?cid=paid_google|||62863&utm_source=goog le&utm_medium=cpc&utm_campaign=&utm_content=&gclid =Cj0KCQjwrsGCBhD1ARIsALILBYpQTU8_aco86w2w4QTUJU5WU pI-t04jThcmmWyoMbFJ8LPh_xvUYs8aArHJEALw_wcB
works remarkably well to clean the rust out or the crevices.
If any head bolt feels like it is turning too easily on the 110 ft-lb stage, STOP, back the bolt out and replace it with another.
Find your engine arrangement, find the right pages for your engine arrangement in part 5 of the parts manual, then use those pages to find the right part numbers in the parts manual. For example, my engines are arrangement 7W7500 and that arrangement is on pages 5Y and 5Z. From there, I can tell that my engines have the 2W8471 turbocharger group which starts on page 38A. This is not intuitive in the least...
Gasket kits are near the back of the parts manual (page 105A in mine) and can save you a lot of money and time. Cross reference the gasket kit with the group number listed to your arrangement page, again, not intuitive...
Don't buy new old stock gasket kits on ebay, buy the latest kits from CAT or CTP. I think the CAT gaskets are superior, but CTP is OK.