On the front axles, the passenger side spring perch is cast as part of the center chunk. If you want to keep the stock width of the Toy, you need to cut down the driver side (long side) roughly 4-4.5" and then you can add the driver perch to gain the proper spring mount width.
On the 9", the center chunk is offset to compensate for the pinion favoring the passenger side. To line the pinion up with a centered tranny/t-case output, the chunk is offset. Shouldn't affect you and is how it was set up from the factory. If you want to have a centered third, you can cut down the driver side tube so that another passenger side shaft will fit in it's place. IIRC this will narrow the axle 3 or 4". It's an old hot rodders trick to narrow a 9" for cheap.