This year my DD was rejected to Lehigh CAS with similar stats (1280 SAT, 3.8 GPA). Visited 3 times, interviewed & kept in touch with admissions counselor.
Improving test scores will help. But in retrospect, I think applying ED was her only chance.
That said, Lehigh has a very specific culture (read the threads about Greek life and the Brown & White online for more insight). My daughter liked everyone she met at the school but was afraid to commit because of the social scene.
Bottom line: do your research and if you LOVE it apply ED.
Good luck!