Finally managed a trip to see Steve and the boys at @CRS Performance this morning... Koni shocks all round, and and a pair of T32 springs at the back later, and there's quite a difference
Not only is the van sitting level, but the ride and handling is massively improved. The local speed tables can now be tackled at a sensible speed without the massive crash from the cutlery drawer, and the van feels far more confident on fast bends, eg the local slip road where you really don't want to lose too much speed before merging with traffic at the top.
Before: 450 front, 390 rear

After: 455 front and rear

Before: 450 front, 390 rear

After: 455 front and rear
