Need help with engine identification
 

Hello,

Bought 1991 W126 350 SDL. Previous owner has told me is an engine was change 3 years ago with 120,000 replacement. But when I asked whats is donor car , he doesn't remember.
So my question how to know if 603.961 or 603.97x?

Thanks

The block should have a casting number on it. There will be a string of numbers with the engine number in it. You'll be a 603960, 603961, 603970, or 603971 in the number string depending on which car it came out of.

Someone else recently asked a similar question in another thread.

http://www.peachparts.com/shopforum/diesel-discussion/389152-w140-300sd-block.html

thanks guy I will report back tomorrow it's too dark now

it's 961. So it's good or bad ?

961 is out of a 300SDL. Block is strong on them. Check the head casting to determine how good your engine is. #14 head is weak, but can be reliable if the engine is maintained and never allowed to overheat. #17 or later is desirable for long term durability. I wouldn't get too hung up on the head issue, I'm running the original #14 on mine, and several others here still have their original #14 with way more miles than I do. More info on how to tell here: http://www.peachparts.com/shopforum/diesel-performance-tuning/373020-1986-w124-300d-cylinder-head-cast-number.html

This is few picture of SDL:

https://farm5.staticflickr.com/4462/...ec922c20_z.jpg


https://farm5.staticflickr.com/4446/...8d0a3765_z.jpg

It's #14. Temp gauge sits always around 80.