My 2nd gen MM/D50 2.6 Turbo Swap

Donor Starion/Conquest info: Any 1983-1989 2.6 turbo Starion can be swapped. For best stock performance the 1988-89 years are best. The 1987 model year had the highest sales, thus will be more available. It is also easy to upgrade a 1987 to 1988-89 ecu. 1983 is the first year and had a different tbi fuel system then the others years and should be avoided due to parts availability. 1983-85 were non-intercooled, thus would make the swap simpler since don’t need to install an intercooler and needed plumbing. 1986 came both intercooled and non-intercooled.
Donor MM/D50 info: 1987-1989 MM/D50 trucks would probably be the easiest to do the turbo swap since they came carbureted stock. Wiring would simpler and an external fuel pump can easily be adapted to the original fuel system. 1990 was the first year using fuel injection for the MM/D50 and was slightly different then 1991-95 years. The original 1990 2.4 fuel injection wiring is integrated with the chassis wiring, thus making it more difficult to separate. But the 1990 intake fuel pump has a higher flow rate then the 1991-95 fuel pumps and in fact has a higher flow rate then the stock Starion fuel pump. A 1990 fuel pump flows about 55 GPH or 208 L/H. A 1990 fuel pump can easily be installed into a 1991-95 MM/D50 changing the intank wiring since they have different pigtails.
Engine: The stock NA 2.6 that came with on the trucks can be used, but NOT recommended since it was not originally designed to run with a turbo (the Starion motor has some internal parts built to run with a turbo). But if one desires, you could at a minimum install the exhaust manifold with turbo, intake manifold with fuel injection, and all the wiring & ecu to run a turbo conversion.
The physical turbo engine swap is pretty much a bolt on affair with only a few mods.

Source