1st off we'd need to see what youre working w/. Some designs of frames wont allow a further swing of the wheels, due to the side of the frame/support rails rub on the tires. If yours falls into this category... the frontend will need to be widened (area between the main frame and the spindles), or a smaller wheel/tire used... but if your planning on going sideways, I recommend widening it regardless of clearance or not.
But to answer your question...
The arm, on the end of the steering wheel shaft, needs to be slightly longer, OR the connection to the spindle arms need to be in further, inorder to allow for a further swing of the wheels... however, elongating the arm/shortening the distance on the spindles (the point where the tierod ends connect), will make steering atad bit harder, due to leverage, but a larger steering wheel or stronger grip will compensate if need be.
Also, while your adjusting for drifting... look into the subject of Ackermann and Caster/Camber (somethings alot of yard/fun karts lack, which hinders ease of drifting)... if you have not yet done so.