dang - welded in 3/16 spacer ring on wheels and still the brakes pulsate

If they were disc brakes I'd say they were warped and need to be resurfaced. For drums you may have a drum that's corroded in one spot, damaged, or otherwise untrue. If the car pulls to one side with drums you probably have one that's out of adjustment, sticky wheel cylinder, etc.

Have you done any work on the brakes? Are they new or ancient?