Outer Limits 4x4 Board

Hey guys. I've got a hilux that has been SASed it's a dualcab sr5 and at around 60 Kms it seems to bounce around. It doesn't feel like a wheel alignment problem but I'm sort of stumped. Mods are SAS with a buds dropped cross memeber and 2 inch springs with standard shakles. I've replaced the t/shaft with a Gibson 1 peice and I have 2 inch hilux rear springs with extended shakles and caster plates. It only is a problem at 60 Kms and fine on the highway. Any help or suggestions would be awesome cheers

Possibly something in the steering??
What mods have you done to the steering??

High steer and a dampener standard steering box. Thought I might just do some measurements and see it the diffs are straight.