Type R Bathurst R coilovers

[cjp]

Hi, I am looking to replace the standard height adjustable Showa dampers on my Type R Bathurst R. It is only used on the road and I don't want to shake my fillings loose. I was thinking about 8kg front 6kg rear for the Spring rates but not sure. Does anyone know the original Spring rates or have any experience of replacement coilovers for street use?