I have a 99 dodge neon. My fpr is a 49 psi would it be a over kill with a 58 psi? Or would it take the fuel it's given?

 

A 1gn neon has not need for a 58psi fpr. There is no benefit, and the added extra fuel will leak down the cylinder walls and damage the engine. Unless you are funning a 2.4L and have a wideband gauge to monitor changes, leave this alone.