You'll want to download the factory service manual from
www.mitsubishilinks.com to assist - that's going to make life easier and save you some cash.
Doing the timing belt, water pump and valve guide seals all at once is a marathon but in the long run it does save time and money vs. doing first one then the other. At least if you're DIY'ing... if a shop does them they will bill as two separate jobs (but if they're an honest shop they'll be kind on billable hours since it will save them a bit of time to do both)
If you DIY the best tool for the valve guide seals - to remove the valve springs - is the official Mitsubishi tool, but unfortunately that's about $450 for the tool itself. I bought one to do mine and my brother-in-law's, and then sold it to Josh @ ADD since he works on these engines more than I do.
The second best tool as I understand it is the Lisle tool, it uses hammers and magnets and magic.. apparently a pretty big pain in the ass on at least 3 of the valves but still doable. There are some guys who argue it's easier to just take the whole engine out for this job so you can work entirely un-encumbered; I actually think they might be on to something. Being serious, once you get this deep in it's actually not much further to just pull the motor and then with it on a stand you can have access to everything all at once.
You're going to want to replace every fluid in the vehicle (yeah every.) and also check this forum for a thread about everything that can leak coolant... check all that stuff. Timing belts and overheating and the "Cash for Clunkers" program are the three top reasons these trucks went to junkyards without a collision.
Great vehicles once you get on top of deferred maintenance!!
