I just rebuilt a 345 out of my 79 scout 2. I had the block magged and bored 30 over. Then i had the heads rebuilt. All the machineing work was done by a very good shop. It was a stock rebuilt except for a compUSA cam and the boreing. It all went back together fine and with no extra hardware. She bolted in fine but this is were the trouble began. It fired up and she ran like crap. I have a 5 pound suction on the vacum fitting on the base of the carb. In the valve cover I have a 10 pound suction. If I remove the oil filler cap the engine will die. I checked the valve guides and they are fine. I need HELP!!!! I cant think of anything else.
Did you check to see if they sent you the cam that you ordered? You might have been sent a much more radical cam than you wanted.Some of these cams that are radical cams don't produce enough vacume to rum power brakes etc.
You may have already checked this, but I think there are some plugs in the intake runners in the heads. If they aren't put back in after the machine work is done, the engine vacuum will pull from the crankcase. Can't think of much other than that that would put vacuum into the crankcase area.