'70 318 BBD falls flat under load

Not to be repetitive, but when you do this is the shot instantaneous, as in right now, or do you get some movement before you see the shot?

Some people confuse seeing gas and seeing gas instantly. As soon as you move that throttle you should see a shot.

IF you are getting some movement of the throttle before you see gas that could be your dead spot. If the problem didn't exist before you replaced the carb then your looking in the right place IMO.

Good point so I just went out and looked.
It is like right now. It sprays instantaneously.