Hi Nick
Haven't run my B4 for a while, but the setup i found worked was
Front
35wt associated oil with no 2 pistons and silver springs, inner on wishbones middle on tower. 30 deg caster blocks with staggered rib tyres. Weight over front where possible
Rear
30wt associated oil with no 1 pistons and green springs, inner on wishbones and middle on tower. Blue Mini spike tyres, maybe with outside row cut off.
I am not the quickest with a B4 but i found this setup quite easy to drive and was able to hold my own
I did notice some people use green front springs and silver rear which i was going to try next.
Hope that helps
Dave