You want to compare that to the market rate. If you want a fixed yield for inflation, you have to buy US governement TIPS. The rates are here:
It ranges from -1.7% for 5 year to -0.29% for 30 year. Yes, these are negative, meaning you will get LESS than inflation. If you can get inflation PLUS 3%, that's a great return, especially guaranteed. There's no way to project stock returns, but here are some expert guesses:
https://www.morningstar.com/articles/1018261/experts-forecast-stock-and-bond-returns-2021-edition - e.g., 0 to 6% nominal for US stocks over 10 years.
If I had that option I would definitely weight it heavily - 50%, 70%? I don't really know. But it's a great option, if you are describing correctly.