WTB: old GM car

I'm looking for a carbureted RWD GM car with a manual transmission. Model not important. Any mechanical condition ok as long as everything's there. V8 prefered, but V6 or I4 ok as long as there's room for a V8 upgrade. Body and frame must be rust free (very light surface rust acceptable)

I'm in Iowa, if you're close and you've got one, let me know