Even if you are making a lot, to then become one of your top 35 years of earning, causing a new SS calculation, it won't change your monthly ss by more than a dollar or so...if even that.
Age 70 and working by: Wendy, www.retirement-online.com
Here is a Social Security and Work pamphlet (online) where you can read/print your answers from.
https://www.ssa.gov/pubs/EN-05-10069.pdf
Here is part of what it says:
"Each year we review the records for all Social Security recipients who work. If your latest year of earnings turns out to be one of your highest years, we refigure your benefit and pay you any increase due. This is an automatic process, and benefits are paid in December of the following year. For example, in December 2018, you should get an increase for your 2017 earnings if those earnings raised your benefit. The increase would be retroactive to January 2018."