The off set of engine is to aline the prop shaft in tye cowl opening.thrust is built in the firewall.did you see the H.9 addendum on mouting a G 23 gas engine, section 12, installing the gas engine. i used one servo and pushrod for ea ELV 1/2. i mounted one servo in the standerd hole and i mounted the other one in the thotle hole. i cut a new hole for thotle. i did not ues the the stock tires or the wheel pants. i fly from grass and needed larger tires. my C.G is at 4 1/4.