Need Front Leaf Spring Help

Im setting up the front end on my project and need to add strength and a little height, Should I add a leaf to the top (short's) or the bottom Longs
I know I can order stronger springs but I have several spare leaves available to fine tune what I have but keep hearing diffeent ideas on adding short or long . Thanks Mike

 

My opinion is if you just want to add height, add a short one. If you want a stiffer spring, add a long one.