With a springer, the axle is pushed out farther than the typical offset of the stock trees from the stem. It would be nearly impossibly to maintain the exact trail, but you might be able to keep the stock rake by finding one that is the same length as the stock tubes. You might end up with zero or negative trail though because of the added offset of the axle from the neck.

It's a bit more complicated than just finding a springer that is the same length.