Use the Sakura X1 rear lower arms and then use the normall suspensionblocks.
You get a smaller rear but more rear end grip.
Mine had the same and was awsome.
I needed to alter the front setup to get more steering
It was a very neutral car after that.
Used the same setup on the TRF as on the Sakura.
Lap times where just 2 tenth apart but that was due to a different motor in the Sakura(Speedpassion in Sakura and LRP in the TRF).