Mercedes Benz

I have a 1973 mercedes 450 sl and i believe the "brain" is messed up. what i am wondering is if the "brain" out of a 1974 slc will work in the 73 by just installing it. i am a relatively poor guy who owns a benz (how smart is that?) and trying to get by as cheaply as possible. thanks

That brain shows the same from 1972 thru 1980