Carr attended Charles Town High School where he averaged 28.9 as a sophomore and 26.7 as a junior before attending Laurinburg (NC) Prep School for his senior year. At Laurinburg, he averaged 13 points and 13 rebounds per game.
In his freshman year at WVU, Carr participated in every game for the frosh squad and was the leading rebounder, pulling down 189 boards in 15 games. He also finished the season in a three way tie as second leading scorer with a 14.0 average. Carr finished in the double figure column in all but a few of the contests. Against Ferrum Junior College he paced the frosh quintet with 21 points, hitting nine for 16 from the floor and sinking three of four free throw attempts. He was capable of playing either the high or low post and used his weight well under the bucket.
Entering his sophomore year , Carr was another sophomore Moran was going to be counting on heavily that year. However, he started slowly, sharing the first team center spot with Gary Reichenbecher. He moved into the starting lineup after the third game and started all but two games after that. He ended the season as the third leading scorer with an 11.1 average and toed with Warren Baker for the best shooting percentage (45.0). He was also the second leading rebounder in the squad. Against Penn State at home, Carr scored 27 points and grabbed seven rebounds. He hit nine of eighteen shots from the floor and nine of ten free throws. Statistically, Carr scored 278 points in 25 games ending with a 45.0 shooting percentage and a 68.7 free throw percentage. He grabbed 158 rebounds and was fourth in total minutes played.
His junior year, he brought down his weight down from a hefty 290 to a much slimmer and agile 230. He started only the first nine games. Larry however played in 18 games, accumulating 312 minutes of playing time. Statistically, Carr made 36 of 96 attempts from the floor—37.5 percent—while netting 12 of 19 free throws for a 63.2 percent mark. He had 79 rebounds and nine assists and scored 83 points for a 4.7 average. Returning his senior year, Carr, in his own words, wanted to "go out smoking" as a West Virginia basketball player.