And Bill, sorry, but there ain't much I can do with that information. At first I thought it might have been one of their 'Cheetah' series GN upgrade turbos, but the 66mm puts us in the dark there. The best I can assume is it is some form of a T3/T4 hybrid maybe? The stock GN turbo was considered this. Pretty much, there are different frame sizes of turbo compressors and turbines, with the t4 and the t3 being the more popular of them all. The t3 is smaller and the t4 bigger. Simply put, the hybrid combines the small, quick spooling t3 turbine with the large, air moving t4 compressor. Best of both worlds. Anywho, heres a little graphic that may help us out. Wouldn't happen to remember the shape of the flange would you? (I do believe this is metric)