Thanks to everyone for their advice
Thank you guys for giving me some advice on my US40. I am definitely going to reinforce the firewall, probably with toothpicks; go with the nylon motor mount so I don't end up adding weight to the tail; beefing up the gear and thinking about mounting the servos in the tail with Kevlar pull-pulls. If anyone has done this please send me details or pics.
Thanks a ton,
T