I just got this engine in my 65 and I fire it up and I open the oil fill tube and it is really hard to come off from all the vacuum when I put my hand in from of my throttle body the car dies I barely feel any vacuum if there is any at all. I cleaned out the valve covers with the pvc they care cleans and clear everything is routed to the factory locations motor is stock from a 2011 Silverado. The only thing I donít have on the engine is the evap. With all that vacuum in the crankcase it sucks the oil from my oil pressure gauge and shows 0 oil pressure. I put new intake gaskets and checked the intake for cracks gaskets didnít do anything and I did see any cracks I even ran the engine and sprayed starting fluid to see I I had a leak nothing. I am lost here never ran into this before any one have any ideas. Thanks for the help!