How likely?

Should I consider UIUC Math& CS a match or reach with a 3.83 UW, 4.43 W and 34 ACT?

On the Application, I listed the weighted gpa as there was room for one gpa.
Middle 50 GPA is 3.75 to 4.0, Middle 50 ACT is 33-35, and Middle 50 SAT is 1470 to 1550. I think UIUC looks strongly at academics and therefore I won’t list ECs.

They don’t care too much about ECs but it’s absolutely worth listing them on your application.

I’d consider it a reach just because of how overcrowded the CS department has been the last two years because of unexpectedly high yield.

Everyone, regardless of stats, who applies for CS engineering, math and CS or statistics and CS, should likely consider it a reach. ECs may help, particularly for such majors because most who apply for those majors have high stats and thus you may need something extra to help make yourself a choice.