I think mine were long enough. Keep in mind, the blind nut purtrudes into the firewall a ways, so the screw doesn't need to actually go past the back of the firewall.

I had my Maiden flight a couple of weeks ago. The plane flew great. It was a bit faster than I thought it would be, but I'm not complaining. I'm running a Saito 1.20 with a 15 X 8 APC Prop. I have a Graupner 14 X 7 3-blade that I'm going to try next. I finally got a chance to finish up some of the details, including the cockpit and gear doors. I'll post some photos of the complete plane when I get it all back together. Here's a couple showing some of the details and the gear doors before painting.