The bottom limb is 2.5" longer from where? The arrow pass? Or the center? If it's from the arrow pass, this isn't too abnormal, as the bow was probably tillered symmetrically. The arrow pass is then placed 1-2" above the center, making the bottom limb longer. This being the case, the bottom limb should be stiffer. The bow sounds OK, and if it shoots well, shoot it. Some pics would be very valuable.