3.5 motor installation

[opopotts]

I have a 3.5 motor and was thinking about installing it my automatic 69 280SE coupe. What do I need to change engines?

[m300cab]

you will need a transmission as well
the 3.5 came w a 4 speed automatic, the 4.5 and 450sl have a 3 speed

[Benz Dr.]

All of the wiring harness, fuel pump, radiator, oil cooler, different front springs, driveshaft, and probably other things I can't think of.

[wwheeler]

Don't forget about the exhaust and hangers. Possibly the trans mounting is different. And just think about all of the electronics for the new Bosch injection system. Yikes! I am sure there are people who have done this, but they probably had a real 3.5 to go by as an example. Is yours a low grille?

[perry113]

My 1970 280se coupe was a Mercedes rescue situation.
It was used as donor car for all of its 111 026 V8 parts and used on 1970 280se cabriolet low grille 6 by the previous owner.
I bought the remains of the car and all of the cabriolet 6 cylinder parts and put it back together as a 1970 low grille 6 coupe.
So everything from battery box location, wiring harness, rear end, driveshaft, engine, transmission, everything that is V8 specific you will need.
My car someday would be the perfect candidate to be converted back to a "real" 111 026 non matching numbers coupe.
You need a complete "very rusted" or crashed 3.5 coupe or convertible donor.
That is for the next owner, not me.
It is a great W111 low grille 6 with some intrinsic underlying value to making it into a real 3.5.
see pictures here.
https://goo.gl/photos/TuCgHGdfBoLQHAX26

https://goo.gl/photos/YmAejCBEGRCjM5Kh9

Also see rescue profile here Hemmings
https://www.hemmings.com/stories/article/swabian-swapping-1971-mercedes-benz-280-se

See cabriolet conversion car here:
https://www.hemmings.com/stories/article/three-pointed-perfection-1970-mercedes-benz-280