When you order the DA 50 order the long standoffs from them as well. I have the DA 50 in my PW and I got the standoffs from them. My engines back plate is not 7" it is 6.5". I put the rudder servo inside the plane with pull pull. Gas tank on the wing tube.
2-1300mah Powerflite batteries below wing tube. Plane balances great. Plane flies great as well.