RE: Tower Hobbies Razor 3D GP/EP ARF 52
Agreed on the 4-40 instead of 6-32 for the motor mounts. I did the same thing -tapped the mount for 4-40 plus added NyLoc nuts to prevent backing out.
I had to use a Dremel emory cut-off wheel to bob about 1/8" off the 1" mount bolts as they were past the firewall and hitting the fuel tank. The removable canopy/foredeck works great on my install. I even opted to use just a simple on/off switch on the fuselage as I can quickly "pop the hood" without tools to recharge or swap the Rx battery easily. Catering to the electrics has made access great for glow engine users as well. ;-)
I figure I'll have 20 to 24 hours in before it flies. But then I usually take a lot longer than the "suggested" time to completion.