currently working on one of these, but have came a to a possible problem. the marks on the firewall and the pics on the instruction manual show the engine being off center? is this for torque or is this a mistake?

Simple answer: It's not a mistake. And your correct again. It's for the torque of the engine.

Each plane has it's own thrust centering. Most ARFs mark them on the firewall. They are mainly criss-crossed "+" slightly to the right of center when looking at the plane from the front. Not only does this aid in the straight line stabillity of the aircraft it also allows the spinner to line up with the cowling due to the right thrust built into the firewall . Line the prop shaft up with this cross and your good to go.

awesome thank you

You'll love this plane with a .40 through .46 engine. I have four of the 40S's and have put together six of them.

See my comments about what to do to it, in the Nitroplanes Support forum.

A few quick and cheap changes will help you a lot.