I' looking to raise my 69 3.5 inches above stock height, will these leaf springs accomplish that?

Yes, these are meant to add 3.5 of lift, above the Bronco's stock height. Depending on your Bronco, top or no top etc, you could end up with a little more than 3.5. Also, new springs can and do settle, so the more you work them, the sooner they will be at their true height.