when I ordered my clutch parts from Phill. the catalog listed early and later chassis #. there is a different throw out bearing and master cylinder for each one. maybe the slave too.
I installed the all aluminium box out of an 82 240 which is the later style.
I also have a slope back iron box, don`t remember the yr I got it out of, but it was an old black rat infested 240. yuk. someone started to pull the trans, it was just in there by 2 bolts, and it just sort of followed me home.
It`s always good to pull the vin plate for id later on down the road. I did on the 82, then just make a notation on the back side. It helped when I ordered the clutch line for the slave. gave the dealer the vin#.
Charlie