transplant
 

I have a 1979 300d wagon with a great engine but extremly rusted body.
I have an opportunity to purchase a 1987 300d sedan with a blown engine but it has a pristine body. ($700.00)
Is an engine swap a feasible option with this combo of vehicles or am I going to run into a lot of problems?

Since you are attempting to put a 5 cyl designed to fit into a 123 body in place of a 6 cyl designed to go into a 124 body, you may as well be trying to install a Ford or Chevy. I'd advise against it.

thanks
 

That is exactly what I was thinking. Thanks for the help.

you could trade your car and engine to a salvage parts place for a good motor for the newer vehicle and have a nice newer benz!