Blown, while reading your forum issue, I recognized those exact same symptoms and conditions that I experienced in my 1990 SC 35th back in August 2007 when it reached 157,235 miles. After the violent episodes occurred two days in a row, according to my records I took my car to the Ford dealer on 8/3/2007 and they changed the camshaft position sensor and said I was good to go. After driving 15-20 minutes the next morning on my way to work, the engine started the same wild bucking, tachometer bouncing from 0-6,000 rpm, coughing, etc. as before the repair. I took it back to Ford on 8/7/2007 and they replaced the crankshaft position sensor, ECM unit, and stator at 157,251 miles. Apparently, that was the fix because I haven't had the problem again up to this date at 210,832 miles. Hope this helps and good luck with your SC because you definitely have the right members helping you now.