Where are you counting the splines? Did you separate the birf from the inner shaft? Are the inner axle splines on the end that slides into the birf 30 spline?
stock Birfields are 30 spline at the hub, and the inner axles are 27-spline at the Birfield end and 30-spline at the differential end. 30 spline Longs are 30 spline at all three points.
Also I've never seen Longfields that didnt either say Longfield or have LF stamped on them.