450SL engine swap - trying again
 

Sorry - first post a little unclear. I have access to a solid '78 450SL - engine thrown timing chain. I am told all else, including trans is good.

I also have access to an '85 500SEL with good engine but weak trans, rusty body. Does anyone know if I can swap the 500 engine into the 450SL? (I know - with enough money and time . . . not sure of how much time I have but if funds were unlimited I would just buy a good running SL) As far as I can figure out, the critical issues are:

1. Will the 4.5 exhaust manifolds fit to the 500 engine? 2. Will the 500 engine marry up to the 4.5 transmission? Based on research here I am fairly certain the motor mounts will work without change.

Any other considerations I haven't thought of?

Many thanks

Who knows?
 

The 450 transmission is a 3-speed, the 500 a 4-speed. Maybe it will bolt up, but who knows? Even if it bolts to the engine, there will probably be driveshaft and linkage issues.

Exhaust manfolds are more likely to work, but again, no guarantees.

Have you tried a search?

Long story short: No, the bellhousing on the aluminum block 500 is much smaller than the 450's, so it isnt a straight match.

A good 560 engine with tranny could probably be gotten cheap enough these days.