BBD will not idle, AT ALL.

im having same trouble.just got my engine fired up after complete rebuild.broke in cam.runs & revs great,but will not idel under 2000 rpms. iv changed 3 carbs now & same thing.im now in process of removing intake & having it milled.it didnt line up good @ all.had to pri one side down to get bolts started so im thinking i may have an internal vacum leak.purchased block & heads already machined & ready.im thinking heads or block or both have been milled.if this fixes it ill let you know,but if you find somthing that im missing please let me know!kevin