is it possible?

[Necrosavant]

to put a 300D turbo engine in a 71 280s w108?

[E-Class Owner]

but would it be worthwhile, or cost effective...?

You would be doing a good bit of custom work to make it all happen... and unless you are really "handy," it is going to cost a good bit of money.

I am just wondering why you wish to take on this particular engine swap?

JR

[cth350]

It's doable. Check with your DMV to see if it's legal to register a gasser car with a diesel motor in it though. You'll be fabricating some custom wire harness details, the exhaust and the driveshaft. Hopefully both cars are automatic or else you're also be playing with clutch/shift stuff. -CTH

[Eirik 400 SE]

Surely possible.. But WHY ???
Why put in those noisy dieselknackers in a car that was made as a smoothrun'in with a straight six..