No matter what, I would still be very leery about buying one. There are some really good '86 and '87 300SDLs out there that can be had for less money because unknowledgeable sellers think that the newer models (ie: 350SDL) are better. As with any engine you may get a really good one or you might get a dog. I agree with the previous thread - if the engine has been replaced with a newer crate engine I would be more apt to buy it.