Holley carb question

[sgt1022]

I recently installed a Holley 3310 750cfm carb on the 300hp 350 ci motor in my 71c10. its jetted 72 in the primaries and 74 in the secondaries. I am experiencing stalling at low rpms, ex. slowing down for a turn or coming to a stop. I recently resealed the manifold due to oil leak. I have a rough idle so I will checking for a vacuum leak at the manifold. Any suggestions on a starting point.