crankcase evacuation?

I've got a 75 duster with a stroked 416 that has only 100 miles on it. I assembled it myself, and the engine has edelbrock heads, ported, air gap intake, hydraulic roller cam .550/.570 lift, 236 @ .050 duration, 10.3 compression. I have a Vato Zone el cheapo chrome breather on one valve cover, and a pcv valve on the opposite to the intake manifold vacuum fitting. My question is, how do you know if you are getting good low pressure or even vacuum in your crankcase? My "problem" is that while driving the car for break in, (still have the hood off), I noticed a little bit of oil on the windshield. On the passenger's side, where I have the breather. Not a lot, but it looked like a fine misting. The only leak I have (other than my drain plug, which I had to replace) is the rear main seal (which is another aggravating subject in itself). Now, the thing that is confusing me is that I don't have any oil that I can see leaking out of the breather, when you take it off and look the foam still looks whitish underneath, the dipstick is not pushing out, and it is not a locking dipstick, and the pcv valve grommet is not really held in that tightly, and it is not leaking or blowing out. Does anyone have any ideas to check this. The car is an absolute brute on the street, and I would think if I had appreciable leakby, or a ring didn't seat or something, that I would have a worse situation than I have going on, but I am not an expert by any means. I just can't pinpoint where the small misting is coming from and I really don't want oil on my hood. Maybe the rings aren't completely broken in yet? Oh, and I have baffles under all my valve cover "openings". Any feedback or opinions would be greatly appreciated. Final thought, I am gonna do a leak down test eventually (I always do on any new engine to get a baseline)