Mmmh what are /180 and /240 ? You mean PowerBook 180 and PowerBook 2400 ? I don't know if their memory cards are cross compatible… But I know until the Kanga , Apple used specific memory modules for PowerBooks. But I may be wrong, someone more knowledgeable than me here could tell you...

Yes I know Kanga and 3400c are not swappable , but there is a thread here of someone who managed to make one modified 3400c card work on a Kanga.