i've just bought cams from a 2002,and the seller give me two new sprocket and bolts.Now my question is, should i change the sprocket in the same time or should i keep my old sprocket?
You can use your original gears, bolts and spacers. I would use the Ford Anderson Motorsports cam changing tool otherwise you will be doing a lot of work to replace those cams. It´s a very simple process with that tool. Your torque curve will be moved to 2500-5500 rpm with the new PI cams compared to the stock 1500-4500 rpm. You can run the stock tune until you dyno it.