This is an outboard spring mount to take place of the foam damper on the LP-86 chassis. This is made to use Losi Mini-T springs. However it seems most are needing softer springs, so you can also use crawler springs from Dravtech shocks are a mini-t based spring and even softer. Can be found here dluxfab.com/dlux-big-bore-springs-p82142146 .
 
If you have any questions please do not hesitate to ask.