How long would you run a stock 22RE before doing "major" preventive maintenance?

I am the sole owner of this 88 4x4, and looking for opinions regarding if/when it's time to pull the motor and "freshen". Pics taken last fall after a respray. I've babied this it's whole life. Currently 320,000 on the clock, and I've done all the service since day one. Religious fluid changes it whole life. Leaks nothing, burns zero oil. Original clutch (yes, original clutch). Only major service was a head gasket at 180,000. Replaced timing chain at same time since I had it open (original chain was nearly perfect). My goal is 500,000.

Common sense tells me "if it ain't broke don't fix it", but the engineer in me says it's a matter of time before I have to replace the clutch, or a broken timing chain (or guide), etc... Other than it being a little low on power, it runs beautifully. I mostly use it around town, but with 320,000 I try to avoid taking it on long trips (out of state) anymore.

Planning to do a compression test and leakdown in the coming months, as a better indicator of what's going on inside, but looking for honest opinions. Am I on borrowed time? Would it be wise to pull it before something fails, go through everything, slap on new clutch to carry me through the next 180,000? Much easier to plan the rebuild rather than being forced to do it after something fails!

What would you do?

 

Sweet!!! I'd be concerned about timing chain.

 

I'd roll with it except the timing chain. Maybe build one on a stand for the ready. Blocks are fairly easy to come by. My 86 22re converted to carb has over 900k. It's dog tired but I'm hoping to hit a million and ask Toyota for a commercial and a new truck 😎

 

Sounds like you've done things right. A compression test and leakdown will tell you about it's general condition.
With 320k on the original clutch I would consider at least having the parts on hand.

Also, I don't know if this is really a thing but I've had several Toyotas and think they're great. But each one has had trans issues around the 150k mark.
I had several different trans guys mention that there is a thing with them. But I haven't read that here, I have read a number of trans posts..
If the engine still tests strong then the clutch & trans would be my next thoughts.

 

Beautiful truck!

I would do the timing chain, and do a compression test just to see where it is at.

Part of me wants to say do what I said above and see how long it lasts (in the interest if science). The engine might be just fine inside other than a timing chain.

The other part of me says to freshen up the engine for reliability.

320,000 on the clutch is awesome! I second having these parts on hand just in case.

No one really knows when something will fail. If the truck was taken care of, it could last a loooooong time.

 

When you replaced the chain @150k, did you use a steel guide kit or plastic? If you used plastic, replace it. If you used steel, run it until you hear the chain.

Personally I would slide an engnbldr cam in and get a few more ponies. The 268C was a very nice improvement to my 22RE. It dropped the need for a downshift in many circumstances.

You can send all 5 injectors to witch hunter for a cleaning and balancing. 300kmiles of gas carries a lot of crud over time.

Beyond that, basic maintenance.

 

At 180, I did a chain and plastic guides. Had the injectors rebuilt at the time (but would do them again, reasonably cheap enough and worthwhile investment) . The guides are my biggest concern. I've been on Engnbldr's site and was thinking the same, cam, fresh valve job, injector rebuild, timing chain, clutch, and re-seal everything. I'm leaning towards getting everything I need up front and planning it in advance so I have minimal downtime.

Appreciate the advice, you guys have been helpful.

 

Clutch inspection hole, got one for a reason. Just saying.

 

#1 Buy a core engine and build it to your satisfaction.

#2 Run your existing one til something major fails.

#3 Spend a couple days swapping out.

#4 Happy, Happy, long time.