Finding an internal vacuum leak

Thank you all for the responses. I've been Dickering around this truck all day, until now. I put a 4011, 650 holley on it and I just wasnt quite happy with it. Fitment issues with EGR and linkage. So I took apart the new 650 that was on it that was sputtering etc... everything clean as it should be for a new carb. I changed all gaskets, new PV and install it. Still has the same issue. I decided to pull the front bowl off and metering block. I changed out the 2 stage PV, for a good ole' standard 9.5 PV. Crank it over and fired off and runs like a swiss clock. That was 2, of the fancy expensive 2 stage pv's acting up causing my ramcharger to act up.
As far as the intake leaking, not sure. Inside the intake clean and oil free. It's due really soon for its next oil change. Maybe I'll start with that, closely monitor the oil level a d order new intake gaskets in the meantime. I do have an Eddy Performer EGR intake I can put on to replace the cast iron one.
Thanks all!