it would be a hard job ! most turbo engines are completely difrent and also run a ecu to control the engine! the only way is to get a complete engine and change it over !
.............also the turbos have different pistons. Not a diesel I know, but a mate of ours had a rover V8, and then fitted a turbo. Took the pistons out very quickly, and regularly cos he just kept fitting the standard pistons (had them laying about). When they run out, he threw the turbo away!
the difference fred is refering to is likely to be the compression ratio, generally turbo engines do not have as high a compression ratio as non-turbo engines. like fred said, get it wrong and your gonna go through more parts than your average motor factors
you can fit a turbo to a di but it blow the bottom end out it put too much diesal in to it just buy a second hand turbo engine there only about 250 pounds