Im swapping out an 84 300d motor (out of a parts car) to be installed into my 83 300cd.I pulled both the motor and trannie as one piece out of both cars ,inspecting both setups, Ive noticed some small diffrences.The vac system that controls some of the shifting the trans goes thru is on the 83 ,the 84 has the electronic piece .Should I go with the vac original?The trannie is a bit different in that theirs a vac line running to the trannie on the 83 ,the 84 doesnt have this item.Im looking at swapping the trannie over to the 84 motor , Im not sure of the shape of the 84 trannie .The trans worked perfectly in the coupe.Ill have the 84 motor with the 83 trannie .

So...what engine is going into what again?