Swansea great Alan Curtis says that if Swansea win a place in the Premier League on Monday it would top his generation's promotion feat in 1981.
If the current side beat Reading in the Championship play-off final at Wembley they will be in the top flight for the second time in their history.
Swans assistant coach Curtis said: "I'm very protective and very proud of what we did 30 years ago,"
"But this definitely would be a far better achievement."
John Toshack was in charge of the 1981 team in which Curtis played a starring role.
Curtis added: "Without a doubt, just for the sheer fact now that the Premiership is probably the most powerful and the richest league in the world [promotion would be a greater achievement now].
"The prizes on offer... it seems to go up every day - it's £90m or £100m, whatever it is.
"The fact that we've managed to manoeuvre ourselves to get into a position to play the likes of [Manchester] United... then yes it has to be."
The previous promotion glory was achieved under player-manager Toshack, who took Swansea from the Fourth Division to the First Division - where they finished sixth in their first year in the top flight.
Curtis says he sees similarities between Toshack, who has managed the likes of Wales and Real Madrid, and current boss Brendan Rodgers.
The Northern Irishman took over from Paulo Sousa in July 2010 and has enhanced Swansea's reputation as a good footballing side, taking them to third spot in the Championship this season with a goal difference of 27 that is second only to champions Queen's Park Rangers.
Despite losing defender Neil Taylor to a second-minute red card in the first leg of their play-off semi-final, Swansea held out for a goalless draw at Nottingham Forest and then won the return leg 3-1 at the Liberty Stadium.
The resolve, organisation and attacking potency of Rodgers' team was there for all to see and Curtis was fulsome in his praise of the boss.
"He's been absolutely fantastic, really top class," Curtis said.
"We've had some good managers, we've had some bad managers, but I've got to say Brendan is right up there with the very best and the very best for this club has been John Toshack.
"It's not just the football side, I think it's the comparisons as people as well.
"They've got this order, got something about them which separates them."
The Wembley final showdown with Reading is not until 30 May and Curtis says that the mood in the Swansea squad is building nicely towards the big day.
"It's simmering I suppose," Curtis added. "The game is still a week away, you wish the game was a little bit earlier, but everybody is bristling with confidence.
"But we know that we haven't actually done anything yet, although the excitement is at fever-pitch at the moment.
"It's just on us to get all the players to focus now and hopefully it should be a fantastic day next week."