i've seen it done before.
the exhaust wouldn't come out the opposite side and the exhaust manifold on the 16v is multidirectional since it exits into a flat dual outlet flange.
i couldn't tell you what size the flange is on the downpipe of the stock Fox but I know it would be easily modded to fit the 16v manifold. other than that I believe the fuel system would work fine since it is CIS-E but I if it has a knock sensor system, which I don't think it does, then you would need
the 16v knock box and not the 8v knock box. intake clearance might be an issue but as far as swaps go it doesn't seem like it would be easier than a MK1/Rabbit swap. i think the Fox trannies are pretty tough (I think they are based on the vanagon/bus tranny design). i have thought that the Fox
would be a cool car to euro also but always thought that it should of been rear wheel drive. of course, if that were the case, we'd see alot more of them on the strip and probably less on the street. if I remember right I believe the had the hump and everything there for adding rear wheel drive but I don't know what kind of setup you'd have to do to make it RWD only.
would be a sick conversion!