Gbee,

I have a YS91FZ on mine. The tank is on the CG. The throttle servo, receiver, and battery are in the rear of the compartment. With no added weight it balanced at 5". I have added 4 oz. of lead to the tail and it balances at a little over 6". Once I have it the way I like, I'll make a hatch and put the battery in the tail so I can remove the lead.

Without some sort of pump/regulator you won't be able to put your tank on the CG with the Saito. However, your engine is lighter than mine and if everything else is pushed to the back of the compartment, you may get close to 6". You may still need the battery in the tail though.

Chris