I've found a good running OM603 out of a 93 300SD. The car has 288K miles, no tag on the block to indicate it is a replacement engine/block, #18 head. Car drove like crap (bad vibrations about 30mph, probably driveshaft related) and the turbo didn't spool thanks to most of the vacuum lines being shot (later 602s and 603s used a ECU and a vacuum system for boost control) but even without the turbo, I could feel this engine has some grunt down low compared to an OM602.

How would I tell if it is still a 3.5L and not a 3.0L? I know some of the 3.5s didn't seem to have the rod bending problems. I plan to swap it into my 1990 300D 2.5 that needs some significant cylinder head work.

Is there a difference in size between the turbo on a 3.0L and the 3.5L? I've got an 87 OM603 with the #14 head that seems to be fine but could pull the turbo off of that if needed because it doesn't have external boost control.

Is there any reason the 722.3 out of the W140 wouldn't work in a W124? I know it uses a different mount, but don't know how that's accomplished. It shifted great and I expect it would hold up better against the OM603 than the 722.4 that's already in the W124.

__________________
Current: 1975 450SEL, 83 300D, 88 Yugo GVX, 90 300D OM603 swap, 91 F150 4.6 4v swap, 93 190E Sportline LE 3.0L M104 swap, 93 190E Sportline LE Megasquirt, 03 Sprinter, 06 E500 4Matic wagon.