I would think the spacing is 126 not 130. Also, no chainline expert am I, but the center point of your 7 speed freewheel is gonna line up pretty much the same as the original freewheel. I am kind of surprised the 7 speed wheel makes such a noticable difference. I would first check dish of the wheel; if your current chainline is centered toward the larger cogs rather than in the center of the freewheel, could be that moving some axle spacers around might be in order.