They are all good, for W123 turbo choices in sedan form, you have 1982-1985, The engine is the same, on the 84,85 the tach works differntly, I like the 84/85 for the 2.88 Rear gears.

they are all good.

The car your describing if it has no rust sounds like a good deal, no blow by... never seen that....

__________________
1984 Euro 300SDC, (4spd standard)
1986 Toyota Landcruiser Diesel HJ60 5spd X2

Gone but not forgotten (some sold, some stripped)
1983 300 SD, 1985 300 SD, 1983 240D, 1986 300 SDL, 1985 300 SDL, 1983 300 D, 1984 300 D, 1985 300SD, 1987 300 SDL, 1983 300 SD, 1985 300 TD Euro, 1983 380SEC, 1990 300 D, 1987 300D, 1982 300D, 1982 300D, 1994 E420, 1987 300 TD, 1987 300 D, 1984 300 D