question concerning a 340 buildup?

The combo you describe sounds like the same thing we used to run back in the 70's and 80's. The Holley strip Dominator with a good double pumper in the 750/800 cfm range will work well if its more of a racing application. On street and strip cars the Performer RPM will make more torque through a broader RPM curve than any of them.I first heard this while talking to Herb Mcandless at a swap meet and had to try one out myself.The Victor probably has a little more plenum volume than you need with that combo.