why does it idle but not take fuel

ok all knowing mopar gods help me out on this.
i have a 69 dart 318 2bbl mostly original.

the car sat fore 3 years with out being run

i have replaced the fuel tank, sending unit, cleaned the fuel lines, tried several rebuilt carbs, replaced the filters, bypassed the existing fuel system with fuel hose and gas can, replaced the timming chain, replaced the vaccuum advance on the distributer, added an electric fuel pump and i am getting ready to replace the intake manifold gaskets.

here is my problem, the car idles perfectly, sometimes it runs out great, i drove it to raleigh and back 100mi round trip to a cruise in and it ran great , except for a few instances of seeming like it picked up trash.
most of the time though it will go 5 or so miles and run ragged, idle perfect but wont take gas, stalls ect,but still idles perfect i want to drive this car to shows this year. do you think the intake gaskets will work or do i have another problem. i am thinking now i have a vaccuum issue.