There is a slewwwww and I mean a slew werth of info on turbos out there on the net. Including flow charts and all the neccessary info one might want to know about a turbo. Garret makes any combination of turbo to meet your needs. I am sure the b-1 is a hybrid of various parts, but from what I have seen from garret, it could be easily one of the t04/t61 combos, depending on the exhaust and intake turbine specs, boost pressures, & of course desired lag time. I am sure an engineer savy tweeker could do it on their own. Isn't that what Kurt did??? The design behind his work takes out alot of engineering on your own personal end. So the price is well worth it. Bravo...