GA pilot reported an NMAC with a helicopter near ATL Class B airspace.

Narrative

While flying a deadhead leg to pick up a pipeline route beginning in FTY airspace; we traversed from ZZZ to FTY north of ATL at around 1000 ft. AGL. We were at this low altitude due to high winds enroute as altitude increased; which we had been fighting for 90 minutes previously after leaving the ZZZ area. While due south of Atlanta's metro downtown area; we observed multiple helicopters operating and believed we had adequate separation from all of them when one helicopter; perhaps an Aircraft Y; evidently monitoring the freeway traffic; reversed course back toward us; causing our TCAD to alert and we initiated a climb. Vertical separation estimated to be 100-200 ft. and zero feet horizontal. I am not sure of the actual separation as we lost sight of them in the climb. We were operating with wingtip recognition pulse lights on; strobes on; and transponder as required in the ATL area. I do not know if the other traffic ever saw us as once they passed under us we did not see them again. Unique factors in this near miss included the time of day (heavy traffic on the freeways); which was something I had not encountered before. Also we did not get flight following which was a mistake in hindsight. We probably could have gotten higher altitudes and maybe a clearance into the ATL Class B above us and avoided this situation entirely. We were monitoring FTY Tower in preparation for entering their airspace but should have gotten flight following and a handoff instead. The final factor was altitude selection. We could have put another 500 ft. under us without a problem in relation to the ATL Class B environment and should have; but let wind conditions dictate our selection. We had plenty of fuel and there was no need to be at 1000 ft. AGL in this area. 1500 ft. AGL or higher would have separated us from all of the rotary wing traffic in the area.