I've finished the conversion:

My setup:

16 x 8 APC E-Prop
E-Flite 60 (400kV) motor
CC 80 ESC
ThunderPower Pro-Lite 4200mAh battery packs. 2 3S2P packs in series.

My bright idea, added slides to the inside of the fuel area, and the batteries sat on a plate, I could then slide the batteries fore and aft to adjust CoG. A pair of servo screws held the plate in place.

All up weight, 8 pounds, 14 ounces.

Maiden flight was Saturday (June 20). I videod it. (Will post when I get it processed.) Maiden could have gone better, the pilot was coming in for initial landing when another anounced his landing as well. My pilot took a bigger swing, and was starting to line up, when power was lost. The plane went in pretty soft, but still broke off the landing gear and broke the prop.

Structural damage is almost repaired. Haven't post-modermed the power failure. THe motor seemed pretty hot. but didn't see any "magic smoke" come out if it. Maybe the ESC lost it. Even thought the ESC is rated for 6 LiPos, I remember reading somewhere that it's not a good idea.. We'll see. First order of business once the plane is repaired is building a motor test stand.