You were going 105 and a little old lady rearended you?
Was she driving a Bristol Fighter?
If she hit you hard enough, there is a chance that your frame was distorted and is putting some stress on the cylinder barrels. You can tell by undoing the top engine mount to see if the bolt holes shift. I have seen over 115 on my speedometer with no ill effects, so speed should not have done anything to it unless there is some other problem such as a pinched breather pipe.
