I think the perfect single for 90's is a Borg Warner SXE 362. I'm running a modified Garrett T04E and runs really nice. I've modified the compressor housing to accept a 59mm compressor and made a T51R mod. For the 7A77's I'm running it's perfect, great response, no smoke and low egt's. Eventually I'll upgrade to 9G90's and see how it performs, but for now I'll leave it alone.