I used to race a XXXT-MF2 on carpet. If you do a search here on hobbytalk for a rollout chart I think you will probably come up with at least one that you can use for the XXXT.
As far as setups go, on carpet I put limiters inside the shocks to lower the truck to about 3/8" ride height.
I used 80 weight oil in all four shocks
I played around with quite a few different spring combinations. It really depended on the track conditions.
I ALWAYS used TM tires. Green's all the way around normally. Sometimes a blue on the right front.
I can't help you with dirt setups. Mine only ran on carpet.