M113 model specifc questions
 

Hopefully there are some M113 experts out there who can point me in the right direction.

Are there major differences between the M113.692 and the M113.693? I.e I'm considering an engine replacement and can't really locate a .692, but there's a few .693's around.

The 113.692 is G500 and the other is from a 500SL.

I understand I'm going to have to swap probably oil pan and some other accessories but my main concern is electrical system. I'm wanting plug and play. I could imagine the cam profile being different also for torque/hp requirements in a truck vs car but maybe the ECU tune takes care of that?

M113 reference guide.
US Model Chart to 1946

BB, consider contacting your local MB dealer. There should be very knowledgeable folks within the MBUSA organization.