Here you will find a few useful factory manuals.
The first link is a 425MB downloadable ZIP file with all the manuals to the entire 1987 Buick car line.
You'll need to RIGHT CLICK and then select "SAVE FILE AS or SAVE LINK AS or SAVE TARGET AS"
Quick Access PDF Download listed below.
200-4R Transmission ManualsPowermaster Brake Booster Manual
Engine Manuals
Turbocharger