My P-60 powered Bobkitty has both Duralites back between the main tanks and flys perfect. Just got done building a P-70 powered Bobkitty and to get the CG the same I had to put one Duralite between the main tanks and one just forward of the UAT. There is one other differencethough, P-60 one has the stock full glass cockpit, the P-70 one has the cockpit kit and pilot.