Caddy suspension

[2low2go]

I have recently had my M4 Caddy lowered by 60mm it was fine initially however now I’m adding weight I am grounding out at the top of my drop down kerb to my drive and grounding out to the point as it has caused damaged, which I’ve been advised is the fuel heater. I am led to believe there are two settings to go on the rear shackles, any ideas how much room that will create as I need to carry another quarter off a tonne!