240Z or 240K box?

Hey guys, I just picked up a motor and gearbox (L24 and 5 speed). the motor has an e88 head, but only a single carb and the gearbox from the outside looks like a Z one. However the sumps not in the right spot to suggest its a Z motor. Any ideas as to what it may be out of, and how I could tell wether its a Z box or not without stripping it down?

Cheers Chris