You just nip the tip. It won't stay in the lsd because the c-clip won't hold, but the axle holds the output shaft in place. Take it to a machine shop, don't use a hacksaw.
And the ABS 300zx unit was the same length as my non-abs 240 unit. While the 240 open diff has a 1" space between the driveshaft mate and the carrier, the 300zx unit has a 1/2" in space, and 1/2" for the ABS crap. It was the perfect length.
-Jeff
-Jeff