No you can not put any Oldsmobile motor into a 1985 Cutlass Supreme. Each car has a motor that was designed specifically for that vehicle. So if you need to replace the motor in a 1985 Cutlass Supreme, you need to find the specific motor for that vehicle.
The ignition wire diagram for a 1985 Cutlass Supreme 2-door, can be found in a Chilton's Automotive Repair Manual. This manual can be purchased at many automotive parts stores, or found in some libraries.
Where can I find diagram of electrical system on 1992 cutllas supreme
You can find it under the dash board.
I have a 1982 cutlass supreme and the diagram in under the hood on a front panel, If not someone may have removed it.
assembly manual off eBay
It should be under the hood of the car.
You could try a 3.1L that is what I have in my 95 Cutlass Supreme SL
junkyards, e-bay or craigslist.
At the firewall on the passenger side
fuel filter is located above the rear axle