before you go any further, get a micrometer.
A cheap digital one from Harbor Freight is all you'll need.
You have to make sure the metering rods are the same length..that could be a problem right there.
Adjustable powerjets are just a different, and better style in my opinoin.
The pill style that you have have a pilot jet in them, you increase the fuel flow by putting in a bigger/smaller power jet.
Some carbs have both (dual power jets)
If you want, someone could probably remove the one you have an install an adjustable one.
That's not going to help your loading up off the bottom though, that's all metering rod.