Let’s discuss smoking.

[Pistnbroke]

Ok gents,
Got a seasonal mud truck keeps the stock L31. So this thing has fender dumps and after this season I’m noticing ALOT of oil coming out of the drivers side head noticeably now due to a direct open header.. so Smokes alot slightly peters off when at temp but minor. Afraid I floated a valve into a piston I did a compression check and it has good compression. Maybe worn rings? But again decent compression 160 across the bank... the heads have less than 100 hrs on them all I can think is the guides or valve seals gave out but that’s a stretch. Needless to say it’s dumping oil and I’d love insight into keeping this engine in the truck.

heads redone beginning of the year (by my engine builder) and the bottom end has 120k ish on the short block.

 

[skylark]

Bad pcv valve will do it.

 

[Erik the Awful]

Check the PCV valve first. Typically, burning oil during the first few minutes is valve seals, and burning oil after warmup is rings. If you floated a valve and it kissed a piston, you'd likely lose compression, but it wouldn't cause oil burning.

 

[Schurkey]

Failed intake gasket can allow oil to be pulled into the port from the lifter valley.

Failed intake gaskets are--or at least used to be--epidemic on L31s.

PCV problems should affect both banks.

Rings can be worn, allow oil burning--but still hold compression.

Any chance the oil-return holes in the heads are plugged with sludge? The valve stem seals could be flooded with oil.

 

[Erik the Awful]

Failed intake gasket can allow oil to be pulled into the port from the lifter valley.
Failed intake gaskets are--or at least used to be--epidemic on L31s.

Solid point.

PCV problems should affect both banks.

Depends on the intake manifold and where the PCV is plumbed. "Mud truck with fender-dumped headers" leads me to believe it's worth checking.

I’m noticing ALOT of oil coming out of the drivers side head noticeably now due to a direct open header.

Is the oil coming out of the cylinder head, or out of the header, or both?

Any chance the oil-return holes in the heads are plugged with sludge?

the heads have less than 100 hrs on them

Probably not. I think your first point is the strongest contender.