Originally Posted by Hatterasguy

Come on Don you should know this by now.

SDL
S class
Diesel
L Long wheel base

300SDL 1986-87 only, 603 powered only.

The 617 was never stuck in a LWB W126 by MB, now by someone else thats another story.

That is correct you do want a 603. Don't worry one day you can trade in that 617 for a good diesel. (flame suit on, running for cover )