UIUC provides its current year’s middle 50% range for test scores and GPA for each college, see https://admissions.illinois.edu/Apply/Freshman/profile. You are within the range with grades better than average but test scores in the lower end of that middle 50% range. Nevertheless, the math score is the more important score for engineering and thus your grades and test scores indicate you have a decent chance of admission.
As to applying EA be aware of the following in making the decision:
The EA app deadline is Nov 1 and any test scores must be in UIUC’s hands by that date to be considered for EA. If you are intending to submit the Oct SAT test, it may not get there in time, particularly if you wait to send scores until after you get them online. Your best chance of getting Oct SAT scores to UIUC in time for EA is to designate UIUC as a college in your test registration as one to automatically be sent scores upon release. That means you send them before knowing the scores. That actually results in the fastest form of delivery since scores are usually sent a day or two before you even get them online. In any event, you should send the test scores you already have by first week of Oct if you want to assure EA consideration. UIUC uses the test with the highest composite to determine admission except the engineering department will also consider a higher math score from another test.
UIUC does not use SAT subject tests to determine admission and thus you need not send them (moreover, sending them is pointless because, if sent, they are removed from the application files seen by those who actually make admission decisions). Same applies to recommendation letters. UIUC uses only grades through junior year to dertermine admisison for both EA and regular admission – senior year grades are used to determine if an admission given should be withdrawn. Thus, there is no reason to wait for later grades to apply RA.
Applying EA gives you some (and I emphasize only some) advantage for consideration for honors, for admission to highly desired programs, and for consideration for scholarships.
You can get one of four decisons in mid-Dec when you apply EA: admit; deny admission; admit to alternative program (meaning you have been rejected for first choice major and offerred admission to something else); or defer to regular admission. Be aware that the business and engineering colleges were known in the past, when there was EA, to defer large numbers of applicants because those colleges liked to see the entire pool of applicants before making many of the admission decisions.
In any event, overall it would appear your applying EA would be a logical choice.