[Snake2998]

I would guess that a half inch spacer at the bottom of each spring will make all the difference. Don't forget that you have almost a 2:1 leverage effect and a half inch will add almost 200lbs of pre-load on each side or 100 lb per spring assuming the springs are 200lbs per inch each so given the approximate 2:1 spring ratio (a wild guess) the spacers will cancel a 200lb passengers weight.