Static NNBS (GMT-900 07-13)

need some help guys. cousin wants to go down an inch on his truck. he has spindles and coil relocators and i told him he could cut some of the coil off to get an inch. so, how much do you cut off the coil?
 
On the red line. I needed an alignment kit but my buddy didn't after we did it. Goodluck to him

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