IIRC the general thinking is just get the non-offset bushings but get a quality one from like energy suspension that will give you the firmness you need.
I got a saleen ones they are made out of aluminum. My car is lowered. I have no idea what these do. I installed them long time ago. My set is offset drilled also. But maximum motorsports sells ones that are center drilled.... what the hell are these for? and what do they do? I wanna know. people say it's for lowered cars but they don't explain what these do so someone explain.
well the poly ones are stiff enough and help keep slop out of the rack. The stock ones are soft and the rack can flex causing a loose feeling.
The alum. ones are probably at least adding to a harsh ride if you have one as they will not let the rack flex at all. In most cases people say poly adds to the ride harshness to an extent as it firms up the movement of the parts poly is attached to (why Ford put softer bushing in stock). So going with a stiffer bushing will add to the harshness factor.
The offset hole basicly changes the mounting point as it lowers the rack slightly. I think there are better ways to get correct ster. geo. than an offset bushing...my .02. The offset bushing can also cause headaches if you added other ster. correcting items for a lowerd car. One reason I went with bullit springs...lowers the car but not enough to get into this crap.