I replaced the chain on my 82 300SD at about 200K. It has not had the oil changed as often as it should have, therefore premature wear.

You did not say if the $600 included a new tensioner. I have been told that is should be replaced with the chain. There are several different one for the early 80's 300SDs, of course mine hadto be a more expensive one at $240. I payed around $140 for the chain, about the say as stated in a early post.

I inspected the guides and could not see any wear and opted not to replace them.

I used the method of using the notch in the cam washer and the timing mark on the cam support/bearing to determine how much chain stretch I had. The old chain showed 10 degrees, the new chain 2 degrees. Tom states that this is not the proper method, but I think will show the differences in the chains.

The differnces I saw in performance was :
1. Much less smoke
2. Smoother idle
3. Better acceration

This was the only work I did on the engine which would affect performance.

My odometer is broken, so I can't check mileage.

Wayne

82 300SD
98 ML320