Kits include front and rear cams. Splined rear cam is included for exceptional load handling capability. Gaskets and bearings not included. Dealer installation is recommended, and special tools are required for proper installation. All EFI models require ECM calibration. This midrange torque bolt-in cam produces peak horsepower around 5800 RPM and installation does not require any headwork or performance valve springs. Should be used in conjunction with open intake and exhaust. This cam provides great low end torque along with good midrange. A good "all-around" cam, the SE-254E is a good match for a light Touring bike - Road King, Street Glide or Road Glide Custom - when the aggressive rider desires a little more top-end horsepower. In a 0-60 sprint or ¼ mile drag race, the SE-254E-equipped model would pull ahead of an identical model with an SE-255 cam. The ultimate in torque cams, this cam offers substantial increase in low end torque for engines up to 110 cubic inches with compression ratios up to 10 to 1. The low end torque increases are great for heavy bikes or for the person who routinely shifts below 4500 RPM and wants the power available to pass without downshifting. The cam still makes peak power above 5000 RPM so people with lighter bikes will enjoy the torque increases without feeling like the bike runs out of air at higher engine speeds.