I believe that decodes as:
F = Flint, MI
7 = July
22 = 22nd day of that month
A (quoting the '58 Chevy Master Parts Catalog) = "Regular '235' -6 cylinder" (with passenger car models listed as original service)
The year was dropped from the later serial numbers from '57 onward, so best indication of year is from the block casting date code located above the starter. This decode is made based on the '58 Chevy Master Parts Catalog, pp 12-14.
Last edited by drdoug; 05/16/2020 3:32 PM.