![Very Happy :D](./images/smilies/icon_biggrin.gif)
Secondly, and this is just my opinion, while the RSR suspension kit is marketed as not requiring any additional chassis strength, I always wonder at what point you would require it.
The RSR uses 698lb/in springs.
That's wheel rate of 433lb/in by them selve's.
That's 4.66 times higher than standard.
Even if you only used 0.5" of spring compression, that is still 349lb/158kg of force
being pushed into the chassis.
The SZ used additional chassis bracing and bonding to hold it's chassis together and they only used 285lb/in springs.