Hello, all - I have a plumbing question for you - can you convert a tub/shower diverter valve into a shower only valve?

I am re-doing a bathroom and find better prices on tub/shower fittings than I do on shower only fittings (which is what I need). It seems logical to me that to change a combo valve to a shower valve would simply involve blocking off the tub connector with a plug or short sweated line - am I right or does this cause some sort of problem? Please and thank-you to everyone!
  3 answers