Here's something I have done in a few of my engines with road draft tubes,including my Cadillac and my friends Nailhead... Road draft tubes are cool but they dont really keep the sludge out of your engine too well,not to metion the blow by that come out of them.What I do is cut the tube about an inch from the 90 find a PCV valve rubber grommet that fits the tube and install A PCV valve,its concealed pretty well since its at the back of the block.You will have to go through the catalog at a parts store.It works really well in keeping the sludge out of the mill. maybe cost you $10.00
Hell I just left the tube, it would leave a spot now and then, but I would explain that it was sweat from all the horsepower. I do agree that a pcv valve is alot cleaner and better for the engine.