Symons, who was 34-of-46 for 505 yards, broke the conference mark of seven TDs set by A&M's Dustin Long last year in Tech's 48-47 overtime win in College Station.
Symons, who left the game with 11:48 remaining, had TD passes of 17, 19, 48, 13, 14, 15, 8 and 16 yards.
It's the third straight week Symons has broken a Big 12 record. Last week he passed for 661 yards and six TDs in a 49-45 victory at Mississippi, breaking the mark of 586 yards he set the week before in a 49-21 loss at NC State.
Wes Welker led the Red Raiders (4-1, 1-0 Big 12) in receiving with 114 yards on six catches and scored twice. He finished the game with 194 career receptions, breaking the school record of 189 set by Lloyd Hill.
Tech jumped to a 17-0 lead and never trailed in the game in which A&M (2-3, 0-1) allowed the most points in school history. The previous high was 57 points by Texas in 1977.
It was the third straight loss for the Aggies, who didn't score until Courtney Lewis' 3-yard TD run early in the second quarter.
Tech has won five straight games in Lubbock and seven of the last nine.
The margin of victory was the second-largest by Tech in the 62-game series. The highest was in 1954, when the Red Raiders went to College Station and beat Bear Bryant's 1954 team 41-9.
Symons fell short of the NCAA three-game record for passing yards. Houston's David Klingler threw for 1,798 yards in three consecutive games spanning the 1990-91 seasons. Symons fell short by 47 yards.