Are you running the rack and pinion steering? If not are you talking about the bearing at the bottom of the shaft or the plastic bushing at the top of column that bolts to the upright?
If it’s that upper bushing you may be able to turn it upside down if it will clear the shifter boss. Another option is a block of aluminum bored for the shaft and then cross drilled to get it as low as possible. Lots of American karts used the block setup back in the day.
How tall are you? If you have the bushing in the lowest hole and it’s still to high what about working with the seat instead?