Jeff_Bubba,
Just so you fully understand, it's not the off center mounting of the engine that creates the right thrust. The firewall must be slightly angled or you'll need to add shims under the left side of the engine mount to achieve right thrust. The reason for mounting the engine to the left of center, (pilot's left) is to get the spinner backplate on the thrust line (center) of the airplane. As stated, most planes require right thrust but some do not.