MOMO shift knobs are drilled much deeper than the stock knob, and the selection is endless. I installed a MOMO knob and a short shift kit. The result is not for everyone: shifts are extremely short and stiff and reverse is a two-hand process, but I'm quite happy with it. These short shift mods cannot hurt the transmission. It is YOU who loses mechanical advantage over the transmission, and long as you don't try to speed shift any faster than you would without the mods the trans won't know the difference. The same Forum member who bought the last of the Ford Racing short shift kits from B&M also offers his own shift knobs. They, too, are drilled deeper than stock and can be used with or without the short shift kit to customize the amount of "shortness" you desire. As a final mod I combined a cut down shifter sleeve with the screwed down knob for a short, stubby shifter.
Howard