Goldberg extra
I have had the pleasure of owning and flying the goldberg extra, all i can say is its a fantanstic aircraft if built correctly.
But i have to agree with the others the DLE30 is just to much engine for that airframe.
The 20 is a much better match, power and weight wise.
like has already been said glue the knock outs in place that run from the gear to the firewall,and i even made a doubler for mine that glued into the inside then added the tri stock.
I think i used 1/16 or 3/32 aircraft ply for the doublers, to help keep the weight down.
Smart move replaceing the stock gear thats a must, the wire is not any good.
I like many others are useing a 120 YS SC 4 stroke.
needless to say it makes more than enough power to fly the plane.
Good luck with your build ill be watching for updates as you continue making progress.