Front coil, Rear leaf springs?

[1986Silverado]

Looking closer at my suspension today and noticed that the front left(dr. side)has a little metal piece between the coils.....I figured that is a spring helper and that the spring had probably collapsed on the previous owner and instead of buying some good used springs or new ones he went with a band aid fix. So, I was thinking of lowering the truck 2/4 anyway. Should I take the helper out or get some springs? Also noticed on the rear springs that there are 3 leafs......and LMC does not list a 3 leaf spring, only goes down to 4. Why would someone remove some of the leafs? To lower it? The truck already sits lower that a stock setup, but I cannot remember the measurements, close to 2 inches lower at all 4 corners.