I recently bought a used 617.951, said to be 15K miles post rebuild.

Got a head rebuilt for it (with the hydraulic pump mount) at a good MB shop , installed that on it and installed it into an '84 wagon.

Compression with newly rebuilt head:
400
400
420
390
380

I put monarch injector nozzles in it, that smoothed it out nice.

It starts instantly every time, with a modest puff of smoke.

My problem is it does pump out frequent puffs, well clouds, of grey smoke.

Other things I've tried that have not corrected this:

For possible turbo seals as the source of oil in intake – I removed the egr gizmo at the front end of the intake pipe .... reached in precisely where turbo air enters the intake pipe .... there was no sign of oil at all inside the intake pipe.

I did a marvel mystery oil soak.

I replaced the little O ring in the inside of the lift pump on the shaft under the roller. Still smokes.

While accelerating hard I smell blowby inside the car.

At idle while fully warm if I place a plastic bag over the oil filler hole it does fill with blowby but not at a pace that strikes me as concerning.

I guess repeat leakdown is next, I didn't record results of the first ... I'm just learning.

For leakdown:

Always done warm? Then you get a cylinder at tdc with each 144 degrees of crank rotation, right? Start with #1 at tdc, advance the crank 144 degrees then #2, likewise with the rest in the order of 1-2-4-5-3?

Are there other possible remedies before the big remedy from Metric motors, currently $4500 for the shortblock.

Thanks in advance.