I have a 1969 and older 24 spline Draco torque converter for a c4. Stall rpm with my 67 Mustang was 2500 rpm with a mildly built 302. RV cam, ported stock heads. The stall on my fox body (much lighter car) was 1900 rpm. As with all converters, car weight, cam, engine power, even rear brakes...