My Gee Bee "Y" project has really close specs to yours.

The original electric specs are:
wing span 40"
Wing area 306 square inches
length 30"
weight 32 oz

I installed a OS .25 la w/ pitts style muffler and the weight is now 47 oz which gives me a wing loading around 22 oz/sq foot

It's ready to maiden but the wind has not been cooperating. I now have 2 new planes to maiden (other one is electric Polaris with LEDs for night flying). Hopefully the wind will settle down today or tomorrow. When I get the maiden done will let you know how it performed.