Has there ever been a 8–3 in the Liga MX?

Yes, 1 time.

The only time: November 19, 1961, Monterrey beat Necaxa (Monterrey 8–3 Necaxa).

Nearby scores

1. 9–2 6 times
2. 9–3 2 times
3. 9–4 Never
4. 8–2 11 times
5. 8–3 1 time
6. 8–4 Never
7. 7–2 17 times
8. 7–3 7 times
9. 7–4 1 time