They clear all stock exhaust pipes, oil tanks, battery boxes, brake linkages, etc.
Materials are better and tolerances are much tighter than in the four speed.
The ratios allow you much more freedom to tailor your bike to your particular riding style. It also makes your bike more versatile. You can have a higher high, a lower low and closer ratio gearing all at the same time. This is the one piece of speed equipment that will increase acceleration, improve fuel mileage, increase engine life, make for more pleasant riding in traffic and more comfortable highway cruising all at the same time and if replacement parts are ever needed, they are readily available at your Harley Dealer. Some inner primary covers must be relieved of sprocket nut clearance and the access cover needs a very slight relief for starter motor clearance.