wow 6.4??? thats high.. but anyways i really recommend you to do single leg depth box jumps but dont use very high boxes just the one that u think ur ready for.. that is for me the single best exercise to strenghten ur legs.. but thats just me.. and i got 3 inches in two weeks by doimg that.. but is up to you offcourse..

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height: 6.1 ft
standing vert: 33 ish
running vert: 35 ish