I'm definately not a carb guru by any shake of the imagination but I do know that the 3310 750 is a vac. secondary carb as is the 4160. I believe the 4150 can be had as a DP or SP depending on which model. The 4779 is a 4150 carb and per the book it is a DP.
Now that being said, if you have a lot of extra money for gas and a healthy engine that really needs that extra gas then just stick with a 3310. Set up PROPERLY it will give you all the performance your street 350 needs.