[L.Fite]

So since you say you have re ringed it couple times, I'm going to assume the pistons and rod bearings are ok, have you had a peek at the main bearings?

If it's smoking it can only be blow by or something with enough friction to get the oil hot enough to smoke,,,
There's only a few things that can make heat...
And I would think anything hot enough to cause the oil to get that hot it will leave evidence.

It's defiantly oil smoke, not steam (cracked block)?

Just thinking out loud...