86 K10 Rear Leaf Spring Help

[Max1775]

I need some help. My truck has a set of 8002 Rough Country 4" leaf springs on the front and 4" lift blocks on the rear. The truck sits considerably lower in the rear and I want to raise it up at least level if not a little higher. I don't like the saggy butt look. I know the stock rears are probably weak, but I'm not sure if I should just swap in a set of 4" rear springs, or if I should go a bit higher. Anyone running a 4" RC lift with the rear springs?