All Lseries boxes will bolt up, just having them to suit cars is a different story.
Datsun 1600, stanza and r30 use short type boxes while the rest have longer ones. To fit a long box you'll need a shortend tailshaft, a new shifter hole sitting further back(also might have centre console probs in a r30? ) and a new gearbox crossmember.
CA SR and Rb boxes can also be used with a Lseries bellhousing, Lseries mainshaft or laygear bearing. These boxes also will need a shortend tailshaft and shifter hole further back than a 240k, zed long gearbox due to the shifter sitting further over the output shaft.