Has anyone done this? I pulled the axle, springs, and mounting brackets from a minivan during a local junkyard's half off sale, so I have about $60 invested so far. I am making a small trailer for my son to use when on vacation, to pull behind his minivan.
Since there are 3 different bolt patterns in use, the 4 lug, small diameter 5 lug, and larger 5 lug, it makes sense to get the same as you have, so you can share the spare tire between your van and trailer. The larger 5 lug (4.5" bolt circle) is the same as most older Mopar cars, so it works well for those cars as well. I can use the same axle with my wheels behind my 79 volare. The wheels have changed over the years in backspacing/offset, so I will build the trailer to have fender room for my wheels and my son's wheels.
There are about 3 different load ratings, smallest will be on the 4 lug vans, highest on the 4.5" 5 lug vans. Some even have truck type second stage overload leafs. Later years have the mono-leaf with sealed bearings. There is an overlap where you can get the mono-leaf with non-sealed bearings.
BTW, anyone in the Phoenix area can have, for free, the brake parts that I removed.