That sounds a little like the oil being sucked by the valve guides. But it would also do the same thing after coasting down a long hill and then stepping on the accelerator to hold your speed.
Is it still going through lots of oil in a short time? (Ex 1 qt in 100 miles is too much on a fresh rebuild.)
I had an old vehicle once that I put another engine in and it smoked like the devil for a while. But it wasn't loosing any oil. Finally figured out that the exhaust system was oily from the old engine and it took a while for it to burn all that old oil out.
