Wing Span: 55.5"
Weight: 5.51lb
Length: 44.5"
Wing Loading: 25.66oz./sq.ft.
Wing Area: 496sq.in
Engine Required: 2c 40, 4c 52
Radio 4~5 Channel 5~6 Servos

At 7 lbs, your wingloading will be over 30oz/sq.ft. I personally would be nervous after the 28 oz/sq.ft mark on that sized plane. I think a .60 is going to be needed for any sort of performance, ie, getting off the ground quickly out of the tipstall danger zone. It may take some work, but can you move the Servo tray farther forward? Replace the wheels with lightweight foam? Using carbon fiber push-rods from Cent. Hobbies can save several oz. in the back. A NiMH battery can save a couple oz over a NiCd. There are other weight saving ideas, others will think of.