How compatible are the engines, transmissions, shocks, springs, engine harnesses, etc..?

1994 W124 420E ---- 119.975 Engine
1997 W210 E420 ---- 119.985 Engine

I found a W210 (totaled, with only 85K miles), and the guy said I could have the engine wire harness for 50.00 if I want it.

Is it a direct swap?

If not, are there any other model years that could be a direct swap?

Looking around for an engine harness......

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1999 Porsche 996 Carrera Convertible
1994 420E - SOLD
1986 300E - SOLD, what a car
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