Dunedin surveyor Toby Stoff has been vocal about Harlech street Ffordd Pen Llech claiming the record from Baldwin St, saying it was not measured using good practice.
He has now bought his flights and will head to the Welsh town on October 25, before returning on November 4.
There he will hire surveying equipment and measure the street using what he believes to be better methodology.
"A friend confirmed that their gradient was measured inside of a hairpin bend," he said.
"It needs to be done from the centre line.
"This is just a fact-finding exercise, just to see how they've determined it."
The trip was funded by his old friends from the Otago Survey School class of 1992 who managed to raise $7500 for the mission.
He would travel alone and a friend from that class would travel down from Aberdeen to assist him.
Mr Stoff has remeasured Baldwin St with his own surveying equipment.
The trip "should be a laugh", he said.
"We're just treating this as an academic exercise. If they still have the record, well done, good job, boys."
There many logistics to consider, such as traffic management while they survey the street.
"It's not like a holiday or anything. There's a lot of stuff to sort out."
However, it would also be a "cultural visit", he said.
The saga could lead to a connection between the people of Harlech and Dunedin.
"We've got this thing in common now. They might think it's great, if they can get a bit more publicity.
"Oh yeah, it's going to be good."
