Yeah tell me about it, Saito is not the cheapest option but they are good engines. On the rudder system, I mounted the servo in the tail and DID NOT use the pull-pull system. Balanced perfectly...

The firewall held up great with my 150 until I pancaked it in on a harrier and the landing gear went flying off and my muffler is sticking straight down and it pulled the top of my firewall out... That wasn't due to the engine though... I crashed. Before that crash the firewall held up fine. I just used gorilla glue to put it back in, it came out clean at least lol.

On the landing gear. Definitely reinforce this area, I did pull out the landing gear mount once. What I did was double up the former that the landing gear block attaches to and I am using (4) 1/4-20 nylon bolts so now the gear will shear away instead of tearing out the bottom of the plane. This is working great for me. Thats what happened when I pancaked it into the runway on a harrier, the gear came off clean with the nylon bolts. But definitely reinforce this area.

Since the new 150's have a rear exit exhaust I had to cut a notch in the firewall for the muffler to come out the bottom. Then just carve a block of wood to make it so there isn't a hole into the fuse.

I have some pics flying my showtime in my RCU gallery also. Check em out