I purchased this truck a few weeks ago and did an oil change on it right away. It has 215000 miles on it. After 1200 miles, the oil level was right at the add line on the dipstick. I added a quart and that brought it up about half way. I have done some reading and found that the cdr valve could be a potential source to this problem. I followed the steps with of the page below, using a manometer connected to the oil dipstick and got results of -1/8" at idle, and -2" at 2000 rpm, so vaccuum pressure at both idle and 2000.

Crankcase Depression Regulator Valve

According to this article, It is not pointing at a faulty CDR valve, though I do have oil on the air cleaner bolt, as well as in the intake manifold. Also, the article mentions that at idle, you should have between 0 and 1 inches of water, not negative values.
What could be the source of this pickup burning oil? Is it the CDR, or some other problem. I have not yet inspected the CDR, and have not noticed any large oily spots on the engine, nor does it leak any oil while sitting or running.