An 'R' and four digit number following is the actual HOLLEY part number, not Ford, which would be on the tag, or often lost. The R number is always on the base.
AND, although conventional wisdom says the smaller jet goes in the smaller hole, sometimes that is not true. It depends on how much air is metered through the fuel circuit, you can have a bigger jet and flow less fuel if the airjet is bigger, or if more holes in the emulsion tubes. Depends on what the carb engineer is trying to do, they may put a lot of air in one to make the circuit do something they want. Like hitting emissions at some certain point in the rpm band.
Yes, I know it's late but thought I'd bring this public service bulletin...... ........