I have recently had a set of SSL King springs fitted all round to the 2012 VE SS M6 Sportwagon series II with the standard shocks.
The car 'looks' a lot better, now it does not have its nose stuck up in the air.

However now when I tow the gokart trailer the rear end seems to bang on the hard bumps and pogo on the smaller bumps.
The weight of the trailer is approximately 900kg, with the ball weight just being able to be lifted by 2 men.

Has anyone had any recent experiences as to using the standard shocks or should I have replaced the shocks with aftermarket units, such as the Monroe as advertised on the King web site ?

Or is there is a better combination, I look forward to any advice.

Thanks