My belief that the OHV (the Vulcan engine is Overhead Valve with the cam in the block; not single overhead cam) engine has a knock sensor came after looking up that part in Rock Auto's online catalog; and finding that they list three different brands of knock sensors for the DOHC engine; but only list one brand for the OHV engine. (Incidentally; the AC Delco knock sensor they list for the OHV engine is the same part as AC Delco lists for the DOHC engine).
However, Rock Auto sometimes lists parts which were never used on a given model; so I can't be sure this information is accurate. AC Delco was the only company that didn't specify DOHC on their listing, but that may just have been that they didn't bother to include that information; and Rock Auto then interpreted the listing as being intended for the OHV engine.
OK; lets assume that your engine doesn't have a knock sensor. I have dealt with Fords before which pinged unacceptably when everything was set to factory specs. These engine often ran better and had more power than the usual examples of that model. One solution, of course; would be to only use premium fuel. Yes, I know it is more expensive, and Ford probably doesn't claim it is required; but sometimes a certain engine, because of the particular manufacturing tolerances (or maybe because some joker put the higher compression pistons from the DOHC engine in it when it was assembled) needs to use high octane fuel. Things like that do sometimes happen.
There are three different crankshaft position sensors used on the three different Taurus V-6 engines. I would also check the photos in the Rock Auto catalog to make sure that someone didn't replace the crankshaft position sensor in your car with one that was intended for one of the other two engine models. If someone put the wrong crankshaft position sensor on your engine; it could throw the timing way off; which would make it ping like crazy.
Nevertheless, there are some adjustments which can be made to reduce the engine's fuel octane requirement. The spark plug gap should be .044" in the OHV engines. This is smaller than the .054" gap used in the DOHC engine (VIN code S); although the plug model is otherwise the same. This creates many opportunities for error, when plug gaps are adjusted. If the plugs in your car were set to .054", this would make the engine more likely to ping. Furthermore; the OHV flex fuel engine (VIN code 2) which was used in some Taurus models used a plug that is one heat range colder than the standard OHV Taurus engine (VIN code U). If the hotter plug for the standard OHV engine was used in the flex fuel engine; it would make it ping much worse.
Using the colder plug intended for the flex fuel engine would be highly beneficial in your situation; regardless of whether or not you have the flex fuel model. And Champion plugs are less likely to ping than any other brand. So I would highly recommend using Champion # 304 (RS9YC) plugs, gapped at .044." I would also replace the thermostat in the cooling system with a 160 degree unit.
These changes will probably do a whole lot to reduce the pinging, but if it still pings too much, I would use only premium fuel, and just live with it.