mac, accelerator pump's ACTION usually can be viewed looking straight down ea. barrel ( 1bbl or 2bbl here?) gotta have a "healthy" , steady ,UN-INTERRUPTED,stream -lasting most of the carb's throttle rotation - like 60-70%. Looking like coming out of a water pistol - for ea. "primary barrel".Now 3rd may actually "demand" more fuel than 4th , power /torque band , and most "upper end" acceleration may only be available in that car in 3rd( 4th just SLOWLY accel's to Top speed? )-SO a restriction like "inboard" carb filter , or inline gas filter. Inside the carb is float needle seat needs proper setting; don't forget the vacuum "power- piston" which controls "metering rods" - if those two components are in there.
A carb " rebuild kit" really would virtually eliminate the carbureter (any filters ,gas,air replace - no brainer
)Such an older car - most carbs over long time get waaay out of adj. ,besides DIRTY (many,many PASSAGES in them) and you never re-adj. & go and use the old gaskets , check-balls,accel-pump,springs etc. which ARE in a kit.