Increase normal category maximum gross weight from 2300 to 2400 lbs. and increase utility category maximum grow weight from 2000 to 2100 lbs. per Installation Instructions, STC SA1945CE, Gross Weight Increase for the C172N with an FAA approval date of January 3, 1989, or later. View PDF on drs.faa.gov ↗

The STC PDF is authoritative: installation instructions, ICA requirements and limitations.