Removing overload springs from 1964 f100?

I just bought my first old school, a 1964 f100. I am hooked and loosing sleep already on upgrades I can't afford. I heard that I can lower the rear end by taking out the overload springs? What are my other options? I am also having a ground problem from what I gather, all lights work but brakes. I also am looking to replace hardware only for inside door latches and window nob that fell off and is stripped.