I want to firm up my suspension and add an inch of lift so what helper springs (overload) are the best to add (as in add a leaf) to my truck? Or did I just answer my own question?

 

Overload springs won't add any static height. Maybe the full length ones as pictured below will, but I've been told they don't. I would imagine they must do something though, unless they just don't have enough arch.

A good friend of mine did a single BDS add a leaf in the rear of his 93 bronco, and got about 1.25" of lift out of it, and it does ride much firmer than before. It's bronc-f250-o stiff, not dump truck stiff.

 

redneck add a leaf kit

 

In the ad the add a leaf syas they add about 1.25 inches so that is all I am after not really necessarily adding lift to the stock height, but for my obviously saggy springs.