These are two stators from the 9.5-inch 245mm GM converter series. This is the converter on which so many aftermarket converters are based in the over-2,800-rpm category. You can easily see the difference in fin angle and opening between the fins. All other components being equal in the converter, simply changing from one of these to the other can make a difference of several hundred rpm in stall speed. With the 245mm converter, there are dozens of possible stator and fin-angle combinations to produce stall speeds from 2,600 to over 4,500 rpm. The trick is to know which combination to use.