What I'm doing this to is an old g-shark. It weighs probably 12 lbs with the engine. So, I think I am definitely going nylon bolts, and keep the 1/4-20 size. I have a stick right now that I made the mistake of going too small on the bolts. I was snapping them like every third landing. You guys are the best! All great advise, and really helped me make a good decision. I hope this place never changes, as well as who comes here.