One thing I forgot to mention, if you are going to mount inverted you need to mount the tank over the CG or atleast back out of that conmpartment. With the Saito the tank needs to be mounted at or below the spraybar on the carb at the rear of the engine, if not it will flood. With the tank in the stock location gravity will siphon you fuel down to the carb and you will most likely have a flooding problem (I did). An easy fix is to loop a long rubberband around the wing tube and the supporting wood and mount you tank on top the wing tube (approx around the CG) loop the rubber band ends around the front and rear of the tank to hold it in place. Because of the angle sloping downward from the nose to the tail, the level of the tank at the wing tube is lower than if its mounted in the nose. Cured my flooding problem. I tried an oscilating Perry Pump before that and it kept the engine from flooding with the tank located in the nose but I couldn't get the engine to run as well as it did without the pump. The Saito 180 does not need any help pulling fuel from the wing tube area anyway.

One thing you guys are going to find if you haven't already is the access hatch in the bottom of the fuselage is too small and a real pain to get at the wing springs. I have seen a thread where a guy installed a top access hatch, he did a great job but it looks like a lot of work and then you have the line for the top hatch where it is cut (which I didn't like). I chose the easy solution I made the bottom hatch longer and eliminated some of the hold down screws(6 screws takes too long to put on and take off and i think fewer to lose is better) to hold the hatch on by making the front of the hatch secured by a piece of overlapping light ply.

While on the subject of wing retention, be sure to use the wing bolts provided along with the blind nuts that go in each wing to hold the wings on in addition to the springs. I talked to a guy not too long ago who didn't notice in those clear instructions they provide that there were bolts and springs, he was just going to fly with springs (I think he would have had a lawn dart if he did).