period correct tunnel rams

[YENKO DEUCE REGISTRY]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Hemicolt</div><div class="ubbcode-body">From what I know, there is a dash and a number after the part number for every time there was a change in the carb.
In other words 1850 would be a first edition, 1850-1 would be second edition, etc.
I can't say for sure what -numbers indicate what year span, but I'm sure someone here or at Holley can tell you.
The 600's I'm going to use are 1850-1. They are all metal with the good metal floats. Everyone is pretty much right about the carbs., 660's are just about made for wide open only and very difficult to make work well for the street. </div></div>

Ok, so I should be looking for 1850's, or 1850-1's, with vacuum secondaries. What about choke? Are the 1850 series all manual choke units?

Also, I see some ad's that say '...not dual quad carbs...', what does that mean? Can't you just mount 2 of these 1850 units and connect them together with the throttle linkage and fuel lines? I'm not trying to make a masterpiece out of it, but want it to be functional and reasonably period correct.