I’m going to apply to Cal poly Architectural Engineering major and wanted to know how difficult it was to get into that major, My stats are a 4.0 unweighted gpa and 4.4 weighted gpa and a 1420 sat
Cal Poly SLO uses 9-11th grades with up to 8 additional honors points for their GPA calculation. UC approved Honors (CA HS only), AP/IB or DE courses can qualify for the extra honors points.
https://www2.calstate.edu/apply/eligibility-index
SLO admits by MCA points. Based on your posted stats you look competitive but definitely apply widely since there are no guarantees.
For 2019, SLO projected 80 spots out of 442 applicants for Architectural Engineering.