I did mine on my 3.2 DOHC. I'm sure yours won't be much different. If you have some patience and a little mechanical ability, its not that bad. You can probably tear it down in one weekend. Have your heads resurfaced during the week. Then, reassemble the next weekend. <img src="/forums/images/graemlins/smile.gif" alt="" />

You have a lot to take off the engine. Don't be intimidated. Isuzus are easier to work on than some domestic models. Take your time. Be careful. Label everything. And don't try to cut corners.
I used plastic wal-mart bags to keep track of everything. Once I removed a component, I would place it (along with all of its mounting hardware) in a plastic bag and label it.

Be sure to have a haynes or chiltons available for aligning the timing belt once your done. A manual will also be necessary for keeping your camshafts in time during removal and installation. These were the only scary parts. I've done it twice(don't ask <img src="/forums/images/graemlins/angry.gif" alt="" />),though, with no problems.

I hope my experience helps some.Good Luck <img src="/forums/images/graemlins/kewl.gif" alt="" />