Both had a teaching background. Both played for and coached Scotland and the Lions. Both suffered defeats as coaches of the Lions in New Zealand; Telfer in 1983 and McGeechan, in 1993. But they used their experiences and struck gold in their combination in South Africa in 1997.
As the Lions prepare for the first Test of their tour on Saturday in Cape Town, the pair said preparation and knowledge of the history between the sides was a big factor in success.
Telfer told the Inside the Tour podcast that from the first press conference, after arriving in South Africa for their tour, they gained an edge.
"History is a big thing in South African rugby and they were world champions who expected to take us apart," Telfer said.
"I remember the first press conference, and at the top table with [manager] Fran Cotton sitting there – a massive man – and on his right was you [McGeechan], and I was on the left, out of the way a wee bit.
"The reporters saw in front of them two Lions who had been with the 1974 'Invincibles', and yourself and Fran had such a reputation in South Africa that they listened to every word you said.
"I thought, psychologically, there was a gain, if you like, for the Lions because of the men who are actually leading the Lions," he said.
McGeechan said he was reminded of the reputation he enjoyed at the press conference.
"I remember it because the Sports Minister (Steve Tshwete) was there, and when we got off the plane, somebody came up to the front and said he wanted to see us separately.
"We got in a room with him, and he went through all four Test matches in 1974. He was with Nelson Mandela at the time on Robben Island [prison]. He said they listened to the radio and the minutiae of what he remembered about the Test matches was incredible.
"He said, 'never underestimate the impact of what you did in 1974', and he shook our hands,'" McGeechan said.
The tour is also remembered for Telfer's famed speech to the team ahead of the first Test, also in Cape Town. It became known as his 'Everest' speech, in which he played on the 'they don't respect us' line.
"For that speech, I had bullet points up on the board, and I used those bullet points to get through to the players. I'd never used the word 'Everest' before in a speech, and never since. So, I don't know where that came from.
"Unless it was from the very fact that I realised that having been a Lion as a player and as a coach, that to win a Test match in South Africa and New Zealand, in particular, was the pinnacle. That's, I think, where Everest came from," he said.
The Lions had a smaller pack than the Springboks and, it was expected they would be steam-rolled. But they used their smaller stature to their advantage, and while exposing the South Africans technically, they were also able to run them around the park.
McGeechan said, "We didn't expect to boss South Africa – what we had to do was take their strength away, so that we were playing to our strengths, and we weren't going to be dominated and play the game that made it easy for them," he said.
Telfer said to achieve the unsettling effect they chose smaller props, Paul Wallace and Thomas Smith, both of them unheralded players with minimal Test experience.
"I have a strange philosophy with props. I like my props to be rugby players first and scrummagers second. I think you can change a player to be a scrummager, but you can't change an out-and-out scrummager into a rugby player," he said.
McGeechan said the tour produced rugby of a quality that he always wanted to be associated with.
It resulted from the communication they achieved between coaches and players and the analysis that went into every aspect of their preparation.
The result was a 25-16 win that proved an important step in taking out the series.