INDIANAPOLIS — Tom Coughlin would spend his nights quietly in his dorm room on the third floor at Sadler Hall, which still was a relatively new residence hall on the Syracuse University campus that fall of 1967 and spring of ’68. It will come as no surprise to you that he was a pretty serious student, even as a senior.

No wild parties. No loud music — the Four Tops were the band of choice on Sadler 3. No Big Man on Campus act. The resident adviser on his floor that year said if you didn’t know he was a halfback on the football team, it wasn’t like he would remind you. Regular guy. Regular student.

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“I figured he’d become an eighth-grade math teacher, that seemed to be the kind of personality he had: pleasant, funny, low-key, comfortable,” that erstwhile RA, a fellow named Jim Boeheim, said the other day from another building on that same campus, Manley Field House, where for the last 37 years Boeheim has engineered his own coaching odyssey.

Boeheim already had known about Coughlin for years before they shared a floor at Sadler, during a time when Boeheim was pursuing a graduate degree and also playing weekends for the Scranton Miners of the old Eastern League.

In a lot of ways, Boeheim and Coughlin had mirror careers as Orangemen. Boeheim started out as a walk-on basketball player but by his senior season he was captain of the team — and also a distinct supporting player to All-American Dave Bing. And Coughlin was a sturdy, reliable running back for the Orangemen …

“But we had a couple of other pretty good running backs, too,” Boeheim said. “One was named Larry Csonka. The other was named Floyd Little.”

From his office on the Syracuse campus, where he now works as a special assistant to the AD, Little laughed.

“I think Tom always wanted to touch the ball more, but the coaches would always tell him, ‘Why in the world would I give it to you when I could give it to Csonka or Little?’” he said. “But I felt bad. I wound up sending him some old tape of him returning kicks and punts so he could show his players, because I doubt they believe for a second that he was as good an athlete as he was.”

Boeheim’s recollections actually extend even earlier than Syracuse, since the two had grown up not 15 miles from each other, Boeheim in Lyons, N.Y., Coughlin in Waterloo, which was only 8 miles south on Route 14 then 6 miles east on Route 96. Coughlin’s primary sport may have been football, but Boeheim also remembers him as an excellent basketball player. In fact it was Coughlin’s basketball coach at Waterloo, Bill Carey, who years later would recommend him for his first head football job at Rochester Institute of Technology.

“He played for a great coach and I played for a terrific coach [Dick Blackwell],” Boeheim said. “Waterloo was just a lot younger than we were, and when I was a senior we beat them pretty easily, but they had some good teams later on. And Tom was a big reason for that.”

Boeheim has enjoyed watching Coughlin’s ascent these past few years — thrilled along with the Giants’ ride to the Super Bowl in 2007, and has kept an eye on the Giants’ rise this year, though he has enjoyed his own forever season, a 20-0 start and a No. 1 ranking for a while. Even if he sometimes has a hard time reconciling the kid he remembers and the man he knows from the descriptions he sometimes reads.

“When I first started hearing these stories about what an intense, serious coach he was, I thought someone was putting me on, because that is so unlike everything I’ve ever known about him,” Boeheim said. “I’ll tell you this, it’s not just that he’s been successful, he’s been successful in New York, and all the stuff that goes along with that. I can promise you I couldn’t have done that.”

Coughlin’s old college buddy, Little, takes it a step further.

“We’re the only college backfield to make it to the Pro Hall of Fame, me and Csonka,” he said. “But if Tom wins next week — and even if he doesn’t win next week — I think we might have a full-house backfield in Canton when Tom joins us.”

He paused. Even over the telephone you could sense the grin.

“Not bad,” Floyd Little said. “Not bad at all.”

michael.vaccaro@nypost.com