I just recently put in a newly used 20r engine in immaculate conditioI just recently put in a newly used 20r engine from a 1980 celica in immaculate condition (less than 100 miles)into my 76 pickup. I noticed some oil dripping randomly now, as I inspected it i found oil with a small mixture of coolant in it being pushed through the crankshaft ventilation hose into my carburetor air filter housing. Does the mixture mean I have a blown headgasket? Why is it getting backed up like that into the carb? I just put a new Pvc valve on it two weeks ago. Any help on this would be amazing!