Thanks to Roger Smith, GM engineers were givin the task of seeing how cheaply they could take an Olds gas V8 and convert it over to a Diesel engine. Its pretty apparent Roger didn't give them the budget to get it done right. Converting a gas engine to diesel in and of itself is not a bad thing, VW did that quite sucessfully with their 1.5 & 1.6 diesels prior to the TDI's. Its just VW did the engineering to make it work well.That's correct, the 5.7 is a diesel design. Different and heavier block, heads and internal rotating assy. The similarities are the sheet metal.