Tore into the ignition system. Replaced cap, rotor, plugs, wires. All were in really bad shape. No improvement in the high speed miss, though. I'm going to change the fuel filter today, and I added a can of injector cleaner to see if it helps. Plugs were worn, but they were REALLY clean. Not the usual tan color you would expect. Running too lean? That's why I'm now thinking fuel problem. Since there were no replies to my original post, I guess I'm on my own. New to this forum. Maybe I'm expecting too much.