you can put a VFD on the motor you have Sonny,but I would test the motor out first if you can..take some basic resistance tests from the motor frame to the phase leads,look for shorts and phase to phase shorts as well..older motors have varnish insulation that doesnt last as long as the newer epoxy insulation. A VFD can also stress the insulation on older motors..The capacitor method of running a 3ph motor on single phase 240v will work at reduced horsepower output..usually 20mfd per HP run and 100mfd per HP start caps. The start caps switch in just for the motor start then the run caps run the 3rd phase. The static converters use this method, they are pretty cheap.