I just got an MCR220 from newegg. From the spec., this radiator uses NPT 3/8" fittings for the inlet and outlet. I tried the Aquaxtreme High-Flow fittings (G 3/8") but they won't fit. The diameter of the Aquaxtreme fitting > MCR-220 inlet/outlet diameter. However, I tried the EK High-Flow fittings (G 1/4") and they fit perfectly. Check for leak and no problem either. What gives?