Easy way to check, if the filler plug is on the right, opposite side of where the exhaust usually runs next to it, it's a 260 box. Even better if you can put it in 1st gear, rotate the output once and count the number of roatations of the input shaft. If it turns almost 3 times (2.9) def a 260Z gearbox. Sometimes may have a 260Z housing, but different internals.