There are two 20g turbos....the beteer of the two is the TD06H 20g which is also the bigger one. Yes there will be a spool difference between the two but i am not sure as to how much. The TDO5H 20g is the smaller more inefficient one. But that of course is my opinion based on people i know who had that turbo.
_____________________________________________ Jerrome B. 1995 GSX - Race 1997 GST - Drive 1995 GST - Who the hell knows