What springs did you use mate?
Are the twin wheel, large mini buses 4.6t? Would the springs be a direct replacement?
Ours are 2 leaves plus one 'helper'.
Not after the extra payload, it is only a 3.5t, BUT, as it is a vehicle transporter, the 'load' will be fairly high up so stiffer springs may help to reduce body roll and improve vehicle stability.
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