Sori 1400 kpa.. Initially the thought was to run the engine for a longer period..meaning a few hrs..

ok i'm assuming you meant 140psi? 14 is rather low ;o)
as for the ring job, what type of rings did you install? if they were chrome rings sometimes they take a while to seat and you will get some oil smoke at first, if moly rings they too take a bit to seat but usually do a lot quicker. The engine may have to run for a bit for them to seat well enough. If you run a 10/30 oil wt the rings will seat faster, then you can change to the heavier weight oil after the rings seat.
I've seen some engines smoke quite a bit at first due to new rings but generally they seat fairly quick (within a couple hrs runtime).

Here in RSA the std oil for petrol is 15w50 or 20w50. Just did a ring job with a good hone, & valve stem seal, new gasket & pressure test on head, compression is on average 14 psi. no Misfires, no oil usage, no coolant usage. engine sounds very good, starts easy. just the smoke issue, check breather pipe, tappet cover for blockage. Waiting for coolant guys to do dye test.. besides than. I'm out of options or answers.. most frustrating.

i wouldn't do the thicker oil, then you'll starve the top end and run into a whole other set of issues and possibly trash the overhead. Oil galleys on the top end are pretty small and that thick of oil wouldn't get up there quick enough when it's cold. I would stick with the recommended 10/30 or 15/40 at the most.
Generally if you have oil smoke the color is more grayish and not white and the smoke lingers more and you'd smell it. Sometimes it's hard to tell though but the lingering effect of the smoke is an indicator, coolant steam goes away quickly, oil smoke tends to linger around longer before it dissipates. With 12k hrs it might be a oil ring issue maybe. You'd generally have low compression during a compression test though. Generally.

Hey Scott.
The head was pressure tested for cracks. came back clear. When unit is under load using hydraulics. smoke is drastically less; I assume it's because revs are down to a minimum. I've driven the unit for about a hour. Mabe i should drive it a bit longer. I had another master technician over for 2nd opinion. however, he thinks that problem is a oil issue. Mabe a oil port is cracked....
My thought is to try a thicker oil. Mabe 20w60 seeing its has over 12000hrs.. before i attempt to strip engine again.

I drove the unit for about a hour with no difference noted. As mentioned before. I disconnected the muffler at the exhaust initially to diagnose the issue.

yep, what scott suggested sounds like a good possibility, coolant/water in the muffler. If it is only doing it after you run it for a bit and mainly when you accelerate that might explain it.
I would run it more, at high rpm's too and monitor the coolant level, the temp, the engine oil, all of it very closely while doing so.
If you had a cracked head or block or damaged head gasket you would see the white smoke immediately usually, since there isn't immediate smoke till you rev it up that makes sense to me too, excessive residual moisture in the exhaust system.
I'd say run it for a bit and see if it burns out whatever is in the exhaust and muffler, it should clear up in a short amount of time unless there is a lot of it in the muffler. Rev the engine to governed high rpm and hold it there for a minute and let it off, and do that several times, that should get the exhaust very hot and should burn out all that left over moisture in it.
Not too long ago i did a head gasket on a PSI engine and when i first started it up it did that, i had to run it at high rpm's for a bit to get the crap burned out of the muffler, it cleared up after about 15 mins of doing that.
If you don't notice it clearing up after that then yes, you may have an issue you did not find or may have created during reassembly.

I read your post looks like you did a lot to try to repair this problem usually white smoke is a water problem first after you repaired how long have you let it run if the same muffler is on the truck the antifreeze might be trapped inside this could take hours of heating to stop the smoke. if you find this is not the case can you tell what cylinder is causing the problem if it smells like a sweet smell a would assume it antifreeze l would than remove the spark plugs and see if a plug look like it was steam cleaned at the tip see if you see any water in cylinder if not pull the rocker shaft off the truck to close the valves install shop air approximately 125 to 150 psi into one cylinder at a time remove radiator cap and let sit look to see if air is bubbling in radiator or over flow bottle for approx 15min if you do not see anything go to next cylinder if you find one that is bubbling or overflows out rad than that is the cylinder that is causing the problem possible cracked head.get back to me with your find.