Heck, on a 305 even the Performer RPM would be a bit overkill. A Victor anything would make for an awful engine that has worse performance than stock with a 305. For a carb, I would just go with a properly chosen Rochester Quadrajet. Just set it up and never touch it again. It will be better on gas and have better throttle response than a Holley 1850 (600) any day! Plus, it is easier to adapt and does not require all those special brackets to work right.