A Cessna Stationair Pilot reported excessive vibration on initial climb and return to departure airport.

Narrative

I departed ZZZ ENROUTE to ZZZ1 Airport. Run up and takeoff were fine. At 1;000 feet AGL I began to set climb power per RAM specs for the engine. I slowly brought throttle back to a target of 30' when around 32' the engine started vibrating excessively. The power began to drop audibly. As I Increased power the engine was surging with changes in throttle position. I immediately stopped climb and requested priority handling to the Tower at ZZZ. In an effort to get on the ground as soon as possible I made the decision to make a landing on Runway XX. I took off Runway XY. Winds were about 3 kts so I did not worry about a tail wind on landing. Landing was successful and I was able to taxi into the FBO ramp under my own power. At no time did the engine completely fail.I was in such vicinity of the airport I did not do a ton of troubleshooting as I had almost assured landing at an appropriate altitude. Engine oil checked fine at 11 quarts during pre flight. Takeoff fuel flow and power were all in their normal ranges. I am not sure if fuel contamination was an issue. I took on about 20 gallons before departing with full main tanks. Aircraft was parked in a hanger. With the dry climate and mostly full tanks I elected not to sump fuel tanks. I was operating on the right tank at the time of issue. Upon landing I did sump the left tank (which was only used for taxi; right tank was used for run up; takeoff and climb) and found no fuel contamination. Both tanks would have been stored under the same conditions at 75% full prior to top off morning of the flight.