Is truck lowered 3", 4"....?

[chukis85c10]

I bought an 85 c10. It is lowered and overall I like the stance. truck has a slight lean to one side. Upon closer inspection before i bought it, I noticed the front springs are not the same and one has spacers attached to it. Almost as if previous owner cut it too much and put spacers on it. I measured all four corners from bottom of fender to floor and got this:

Driver's side - 29 1/4" front and back (attached image)
Passenger side - front 29" back 30"
Looks like back has flip kit.

I want to level out the truck and do it right. Would this be close to a 3/5? I have 20" wheels with 275/45/20 on all four corners. Any help and suggestions is greatly appreciated. Thank you.