25/30mm drop do I really need castor adjusters and shock upgrade?

[Shiny Alex]

Looking on Ebay and some spring sets recommend upgrading shocks and camber adjusters and some don't?

I'm looking at King Lows due to my driveway and Mount Everest speed bumps into work and as the prices here in NZ are ridiculous (NZ$440 just for springs and NZ$800 for supply and fit) I.m looking to pick them up from Ebay and these seem ok HOLDEN VE COMMODORE FRONT AND REAR "LOW" KING SPRINGS | eBay

 

[Aussie Willy]

all your answers are here mate GSL RallySport

 

[greenacc]

If you want a nice ride you need nice shocks to match your nice springs. Even more important if your car is anything more than a few months old, as stock holden shocks are too soft to start with.