No, no change its just that the orignal frame was designed for those tiny screws that go though it and one side of the frame has larger holes then the other. I found that taking two 2-56 allen head bolts and cutting them down so they only go in half way on each side works better then the supplied 2 screws. Do not leave these out as they support the frame behind the motor where it breaks and that is one of the reasons you bought the mount, the reason they have ovel holes for the minor diff in the frames in this area on each side. Also check to be sure you cut out enough of the mount to fit the frame stiffener properly as it provideds a spacer and flat mount for the motor however if the stiffener is not sitting flat in the frame the motor will twist and this will affect the mesh of the pinion with the main shaft. My stiffener had a burr on the bottom and I didnt notice it till I was tightening the motor and noticed the motor was cocked to the side.
If you need long replacement bolts there are sold as muffler bolts in LHS.