Hi everyone I am new here and wondering if I could get some help. I had a pretty good leak in my front cover and tappet. After I replaced the gaskets I was starting to get some large amount of oil coming out of the blow by tube. In fact I drained the oil out of the tube in about 400 miles. The strange thing is the oil only blows out at about 70 mph? I am in the process of checking the vacuum for leaks. I get 22 hg consistent but it falls to about 8hg in about 30 seconds? That test was right off the vacuum itself? I do have oil around where the vacuum attaches to the front case? Any ideas or suggestions? Also how many hg on the vacuum should it hold after it is turned off? Thank you everyone for your help. I have not figured signatures out yet but the truck is a 1998 shortbed ext cab 12v cummins 60lb over springs, 4k Governor springs, 300 hp injectors, upgraded clutch, manual transmission, 62/80 phatshaft turbo with AFE stage 2 intake.