Forget UT. If you are not in auto admit numbers, your son will not get into engineering at UT. With that class rank and scores, he will be denied holistically. My son was near top 10%, 2210 SAT, 1430 M+CR, National Merit commended, 4 PLTW engineering classes, current internship at Lockheed Martin 8 hrs a week that will go through every summer he is in college, and was offered waitlist, CAP and PACE thru UT.
Your son will get into Iowa State, Oklahoma State (middle daughter attends there-great school. College Station bigger than Stilly) and OU.
TAMU is a BIG maybe for engineering.