Has there ever been a 11–3 in the Liga MX?

Yes, 1 time.

The only time: June 18, 1972, León beat Torreón (León 11–3 Torreón).

Nearby scores

1. 12–2 Never
2. 12–3 Never
3. 12–4 Never
4. 11–2 Never
5. 11–3 1 time
6. 11–4 Never
7. 10–2 1 time
8. 10–3 1 time
9. 10–4 1 time