Been good reports on ESPO. 1" more arch than stock. JR spring (JC Whitney) is good if they send you the right ones . You could dissassemble yours w clamps & have a suspension shop add some arch to the main leaf then take the 2 mains home & reassemble possibly adding a leaf or 2 from your stash. Jack up the rear in the center of the bumper till it's where you want it/looks good & measure the difference then give them that dimention. I forget which half of the spring is for height/stiffness/launch etc if you are adding half leafs or just a whole leaf or 2