[Leeroy]

By placing on an angle you effectively reduce the surface area of the radiator and therefore reduce the cooling efficency of the radiator. I am using the standard VN radiator which I have mounted vertically but you guys are using high efficency radiators with 2 rows and probably more surface area than a VN. I wish I had the space between top of radiator and body to give a nice open clean air intake which you would be able to get when you mount yours on an angle. To answer you question "who knows".