I got the wing completed this morning and am moving on to the fuselauge. Looks like the off center mounting of the engine is to compensate for some angle that the firewall has built into it. I suppose the spinner will be in the center once the mount is installed. Still looking for some one who has installed a 46 or 50 on their U Can Do. Did you have to shim behind the mount to get the spinner/cowl to have the right clearance?