There is a little more differences between the 4150 and 3310 than some people understand. The DPs have different boosters, usually have 4 corner idle, progressive secondary throttle linkage, and of course, another accel pump assembly. They have much snappier throttle response due to a stronger signal and are calibrated with richer idle and air bleed circuits. They cost nearly twice as much and suck down fuel at alarming rates. But they can wake up an engine. I have owned the 600 and 750 vac secondary carbs and several DPs- the DPs are just a better carb for a serious build.
In fact, I just ordered the 750 HP main body for my 750 DP. My 530 HP 408 can probably use a few more CFM than the 750, so I thought for $125 I'd try it before I maybe get a 800 or 850. BTW, carb prices are getting ridiculous!
Why are you trying to confuse the guy?
There is so much wrong with your statement, I don't know where to start!
4150 is a carb family designation, as is 4160.
It has nothing to do with the specific carb part number 3310 or how many accel pumps it has.
DPs do not have 4 corner idle as a group.
DPs do not have annular boosters as a group. (You didn't say 'annular' specifically, but they are pretty much the only choice of "different" boosters.)
AND under a different part number, a 3310 can be a 4150 with only the addition of a metering block in the rear. As a 3310, it is a 4160... as a Street Avenger, it is a 4150, but still only has one accel pump.
A single pump, vac secondary, has the exact same accel circuit, therefore they can be just as "snappy" as a DP... Sometimes snappier because you are not force feeding a second accel pump circuit.
AND they all have "progressive" throttle linkage as the only other choice is 1:1 throttle linkage. Just that the DP is progressive mechanically, the VS is progressive at the will of the engine. Not to mention that you linked progressive linkage only to the 4150, when a VS can be 4150. You contradicted yourself.
I will get off my soap box now, I don't really mean to sound like a d!ck, but posts like this confuse the thread when we are making progress helping someone.
Carbs are hard enough to work on over the web, without having misinformation tossed in.
Done
Dave