Lower ball joint question.

Back in the day everybody ran big and littles. Sometimes really really bigs in the back.
Since about year 2002, on my 68 Barracuda, she has always run 15s on the back, and except for a short time always has run 14s up front. She has never carried a spare, and I only ever had one flat on this car, and it was just 3 miles from home. That would be in 125,000 plus miles now.
The point is you can only carry one spare. And only the front one will fit in the well. And only if it is close to the stock diameter.
And our cars rarely had rims that matched front to rear. Often Rallys in the front, and some heavy steelies in the back, that we stole off Dad, or the local gas station, and had widened and the spiders moved. The richer boys had Cragars or some other heavy steel wheels. That's all we had. I still have some of those in the basement.