1990 Cadillac Fleetwood Cadillac died while running, now wi

Changed Ignition module, changed plugs plus wires, changed rotor, changed distributor cap, new battery, new alternator, new belt; still no spark.

Changed gas tank and fuel pump last year. Could it be either the ignition switch in the sterring colum or feul sending unit? Unless you suggest somthing else. I am at the point of giving up and sending this no rust immaculate looking car to the dump.

Your help is greatly appreaciated.