See if you can borrow an incidence meter and make all of the checks. Wing, stab and engine. Carefully recheck the CG, fuel tank empty. Make sure elev is at Zero with stick neutral. Make sure both ailerons are at neutral (not both up or both down). Check control throws again as well.

Try again. If the plane is in CG limits it won't matter if the engine is at the firewall or a foot in front of it. Well OK, it will a little but it will still be in balance.