Our only remaining peach tree was covered with blossoms this spring. Most of them must have been pollinated because the tree is simply covered with peaches. Every time I walk by I try to shake it to get some of them to fall. There's no way that tree can support anywhere near that many peaches, unless they're no larger than marbles.
My understanding is that an elderly or distressed tree will produce extra fruit in an effort to pass on it's genes. Maybe it's time for me to to plant another tree?
It that idea is true your tree must be in good shape.