Well, I got it all together and gotta say, this is a nice arf. I forgot to add any thrust to it. It recomend 2 degrees. I've already mounted the engine and cowl. I'd have to drill new holes and remount the engine. You think it will make any difference if I leave it straight? What can I expect on the first flight?

I gave my sukhoi ( with an inverted 4 st) 2 washers down and right thrust. that is to say no washer on the bottom right, 2 on the diaganals and 4 at the top left point. If you kept the 45deg down mounting that is stock then 2 at the bottom of the engine will do. In any case the setup I have on mine trims nice n and straight .

To tell you the truth I let my friend do the maiden, at the time I was not confident of my abilities. I didnt need much trim, some up elevator as I recall. Moine lands a bit fast but is managable.

I would make the changes if i were you. Ive botched engine mounting before, a bit of a pita but no big deal. I dont know about the giles ( i havnt assembled mine yet) but the cheesy engine firewall screws on the sukhoi were too short with washers so i bought some nice chrome 3 mm socket head screws. These planes are kinda heavy but they are tough, Ive made some crappy landings and only bent the lg. Other planes would have come apart.
What engine did you use?

I really wanted the Sukhoi, but Tower raised their advertised price by $30 and would not honor the advertising, so I got the Giles. I decided to put a YS 53 I had. I will probably put the mount and drill another set of holes in the firewall, fills the old ones and line up the cowl again. BUt I think I will fly it first to see how it flies.
quote" If you kept the 45deg down mounting that is stock then 2 at the bottom of the engine will do."

DOn't quite understand this statement. But I had to remount the mount to put the engine inverted. DOes the mount have any thrust built into it? I must confess I did not check that.

On my giles the motor mount was allready installed at 7:30 if you were looking at it from the front., the top of the motor is down and to the left. This would line up the exhaust to exit from the bottom cutout. If you shimmed the top and left (sitting in the plane) sides of the mount you would get the appropriate thrust. I dont know about the YS 53 but the 63 is great on the Sukhoi. I did increase the tank size 4 oz though. Dead sticks can get ugly if you are not on your game.

I did not use the 7:30 position. I wanted the engine hidden in the cowling so I inverted it. Looks very nice. But when you add washers you change the point at which the engine exits the cowling. You then must crook the cowling which looks awful or move the engine mount off center to the left to compensate for the change.

I moved off center to compensate. Who knows , it may work as is. It may not be bad at all, It may have a very marginal effect on your setup.
I suppose if you find trim problems at varying speeds it may be related to thrust angles.