General aviation pilot reported a near miss with another aircraft during cruise. The pilot took evasive action to avoid the aircraft.

Narrative

I was capturing a survey grid over and around ZZZ. I was at indicated 7400-7500 indicated altitude; travelling north on station. I was on VFR flight following talking to ZZZ Center on XXX.XX. A severe clear VMC day. Aircraft Y I believe departed from ZZZ; was climbing northwest of my position heading southwest. He was talking to Center on my frequency. ATC advised them of Aztec traffic above them at 7500. I was not the Aztec in the area as two other company aircraft were nearby capturing the same general area. I was unsure which aircraft they were. I was quite focused staying on line for my capture; hence why the flight following; but I began keeping an eye out for this aircraft below me. I expected the aircraft to stay below me until I passed. Out of the corner of my eye; the aircraft became pictured on ForeFLight. The Sentry in the plane is not the most reliable and has blackouts at times. The target on the screen quickly showed the altitude difference shrinking. ATC then asked if Aircraft Y had the Aztec X traffic in sight. They told ATC 'traffic in sight.' I began looking. Did not see anything. Then ATC asked if I had traffic in front of me in sight. I was about to call and say no visual when suddenly I spotted the aircraft directly in front of me; same altitude. I snapped the yoke over hard left into a 45 degree bank while simultaneously calling traffic in sight. The aircraft; a PC12; passed off my right between 200 and 300 yards. To my surprise; ATC; or the other aircraft seemed to have any clue of the near miss the just happened. I circled around and re-joined my line; and the PC12 left the area like nothing happened.Personally; I'd say I should have kept better situational awareness before the event happened. That being said; I should have had the right away; and I was very disappointed in ATC and the other aircraft in that situation. I was not asked about that traffic until it was right in front of me; closing in head on. Just glad I saw the other aircraft and avoided a very bad day.