I see what you're saying, but if you put one that is taller on, it increases the height at which your hand could potentially rest. You're a guy, right. Let's say your Johnson is 6" long, well there's 6" of stuff to grab. Well let's say, you're only 2"...where those only 2" of stuff to grab. Get it? And some knobs do go further down on the shifter itself than others. Some shifters come with a sleeve that's only like 1 1/2" in tall, so the knob only comes down so far. If is has the longer sleeve. it will go down further. That's all i'm saying. I have like 4 different after market knobs, but don't like any of them now with my yellow shift boot.