Hi all,

I realize most of the chatter has migrated away from the forms at this point, but I unfortunately still have a great deal of respect for the forum format (searchability, archival, quality of information, etc.) so I'll post here even if nothing comes back to me.

Have a 2001 FWD Aztek (Mudmobile) that I picked up November 2017. Currently has close to 210K, and I've personally burned 51,000 miles into it. I've replaced the spark plugs/wires, motor & transmission mounts, rack/pinion, tie rod ends, all shocks/struts, Radio head unit, speakers (premium), wheels (premium aluminum rims), tires 2x, alternator brushes, belt, tensioner, installed a trailer hitch and RV plug, the list goes on...

In spite of all my attempts to thoroughly disintegrate the transmission (towed a 2k pound trailer from Portland, OR through Yellowstone back to central SC), I still only had minor slipping/thudding into gear, which has basically been resolved by a bottle of transmission stop slip I picked up a week ago. Recognizing this is not a permanent fix, I'm still in the market for a donor powertrain. Fortunately, a reliable one just showed up for the incredibly reasonably price of $450, with only 79k miles on it, and comes with a car attached. I'm planning to pick it up this weekend, and hold onto it for a while before I actually enact the swap. (subframe is rusted out, as it's a northern car) I also have a set of shop manuals, a decent amount of mechanical experience, and a lot of willpower to guide me (usually in all the wrong directions.   )

The question I have is: while the engine is out of the car, what refurb should I be doing on it so I don't have engine issues down the line?
My list thus far entails:
Serpentine belt
Belt tensioner
Water pump (heh heh heh)
Spark packs (I have old ones, and I have rusted ones. I'm thinking new ones are probably in order. )
Exhaust gaskets (duh)
Timing chain (to allay future maintenance issues)
Motor/transmission mounts
Anything else listed in the book.

Anyone have experience in this area that can tell me the obvious issues I'm overlooking?

EDIT: (apologies to anyone who saw the triple-post. I encountered some "database issues." Should be sorted now)

I would seriously consider replacing the rack and pinon and lines if the engine is out and never been done before or appear to be seeping and/or leaking. Doing it with the engine in the car is a pain. Also take a good look at the hard brake lines and fuel lines as they should be extremely easy to reach right now.

When I had the heads torn down for gaskets I addressed these issues to save some headache down the road. Hope this helps.

I'm glad to see the site come back up.
It's been (quite) a few months since I started this interminable project and here's where we're at:

The engine swap went off reasonably well. I damaged my intermediate steering shaft linkage because I'm a knucklehead. I also drained my A/C and disconnected it instead of just pulling it out of the way. Big regrets there.

Turns out the donor transmission was not "perfect," but in all reality was good for 1st-3rd gear, and simply had no 4th gear.

Of course, I couldn't learn that until everything was back in the car, so I ended up dropping the subframe to get into the transmission, following the shop manual (a fool move on my part), which resulted in taking the valve body APART instead of OFF, and the ball bearings went EVERYWHERE.
I could swear to you I put them all back in...
And yet, I still found one left over when scrounging around for my lugnuts...

Now the car hard shifts, slips out of gear on the way into second and whines from second through fourth.

Transmission shops won't help me out, so I'm heading out to try and put it back together on my own... What could possibly go wrong? 

Takeaways so far:
Take your brake calipers off and hang them on the struts, don't disconnect the lines unless you want to spend half a week bleeding the car.
Always unhook your intermediate steering shaft linkage.
Don't follow the shop manual when pulling out the valve body to get at the 4th gear spindle.
Don't overtighten (even a little) the stud on the starter. It will snap off.
Wiring harnesses aren't easy, but far from impossible (fight me, random wire I couldn't find the terminal for)

GO to junkyard and get another complete valvebody, hubs had to do that too, worked fine. Of course, when he replaced the 4th gear clutch hub shaft, it only made noise. Apparently the gears that the splines were stripped too so it needs a rebuild. We haven't done it, but we've taken it to Dallas and San Antonio and back with just 1st, 2nd and 3rd with only a minimal loss of MPGs, like 1 or 2.

I learned some new information... At the expense of much frustration.

Ordered a valve body, realized it was a piece of crap, took the parts I needed out of it (check valves, gasket, filters), cleaned them, reassembled my own valve body. Found out the 4th gear friction plates (name may be wrong, sorry, been a while) slipped off the end of the clutch hub and chewed each other and the clutch hub up. Possibly because I forgot to reinstall a piece that sits between the clutch hub and the valve body.

Put it all back together with some sensors I pulled off an '03 (BAD, BAD Mistake) and...
It didn't work particularly well.

Slipped in and out of gears, generally fiesty and unfriendly.
... Also pouring fluid out like there's no tomorrow.
Turns out I over-torqued a bolt on the case (we aren't even going to discuss the 2 stripped out star bolts that I had to use an extractor to remove, which, of course, were replaced with standard dadgum bolts) and cracked it but good.

Slathered it with JB Weld in an attempt to make it back to the worksite (25 miles from home), and barely made it in as my driver side wheel bearing disintegrated (over-torqued that, too, apparently)

Trip to a junkyard yielded the pan and a bearing, pulled it back apart, slapped it back together, made about 5 miles of test driving ok, decided to go home with it, and less than 1/2 mile for the worksite, the torque convertor clutch entered a fail state and will no longer engage.

So
Now I have yard decor with a running engine and inoperable transmission.