putting a 1980 engine in a 1979 300TD
 

HI, my wife has a 1979 300TD and the engine blew. We took it to the local benz mechanic who said that he had an engine from a 1980 that he could put in for us. When we went to pick it up, he told us that the 1980 engine didn't fit with the suspension system in the 1979, so he took it out and replaced it with new shocks. After 1 week of driving, it started making load noises after going over any bumps. We took it back in and he told us "I"M going to have to research the shocks to see how we can correct ther problem" MY immediate thought was- maybe you should have done that beforehand.
My question is whether he should have put the engine in in the first place if it isn't appropriate to do so, and if it is possible to correct the problem, how can he go about it. He did give us a warranty, so I would like to see exactly where we stand

Thanks for any help you could offer

Eddy