53K and no codes, right? Then you don't need to change the O2 sensors. Heck, I wouldn't even change the spark plugs and wires for another 15K or so if it were mine, but that of course is my own preference.
IMO, if you really want to do some preventive maintenance on your '98 Vulcan, then you should make sure that your Sable's cooling system has been serviced, and a by-pass kit installed, according to Ford TSB Article No. 01-11-6. READ HERE.
If the kit is already in place, then flush the cooling system good and refill with a 50/50 mix of antifreeze and demineralized water. This should be done at least yearly.