The pair look the team to beat in Sunday's opening round at Bruce McLaren Motorsport Park in Taupo. Round two is at Manfeild on December 11 and the big finale at the Cemetery Circuit in Wanganui on Boxing Day.
NZ Suzuki Series 2016 is New Zealand's largest motorcycle series with top riders competing from New Zealand, UK, Isle of Man, Europe, Japan, USA, Australia and, this year, 13 times Isle of Man TT winner Michael Dunlop.
But among the sidecar entries, Holden's two TT victories - in 2011 and 2016 - stand out.
Sidecar passenger Shorter, 41, who has twice raced Isle of Man with driver Colin Buckley, is excited about the prospect of competing for the first time with 60-year-old Holden.
"But we have forged a relationship, with us going over and doing the worlds and that. John discussed with me at the TT that he would be interested in doing the series and I jumped at the chance. What an opportunity.
"To be able to be on the bike with him as a current TT winner, well it doesn't get much better than that does it. I sort of have been pinching myself a bit for the last month and now it is actually here it is even more exciting I think."
Holden and Shorter will compete using the bike Holden won the TT on in June.
Isle of Man TT winner joins Tauranga team in NZ race
"I am looking forward to Wanganui really. I think racing on the roads will be my thing," Holden said.
"There are not many (street circuits) left for sidecars."
Holden first competed at Isle of Mann in 1988 but had a break from competing there until 1996. He has not missed a year since and now has two titles.
"Just going faster", is his straight forward reason for his recent success.
His victory in June was marred by four more fatalities during the event, including sidecar competitors Dwight Beare and Ian Bell.
They took the death toll to 252, including seven New Zealanders, at the Snaefell Mountain Course circuit in TT and Manx Grand Prix races since 1911.
Holden admits the loss of Bell hit him hard.
"This year, after Ian Bell got killed, I had to seriously question what I was doing. Ian was a similar experienced guy to me, on similar machinery and everything.
"I did question myself. If I stop racing does that guarantee anything? And it doesn't. And if I carry on racing, does that mean it is going to happen to me? And it doesn't.
"So why stop myself doing something I really enjoy. TT is the best sidecar or road race there is. It is something else."
Shorter compares winning Isle of Man TT to winning a gold medal at the Olympics.
But his golden moment will have to wait for now.
He has decided family comes first so he will not be returning to the Isle of Man next year.
"Definitely next year for me is not on. My son's birthday falls right in the middle of TT week and for the last two years I have missed it," Shorter said.
"It is a big one for him as he is 10. My wife is very pleased."
- Bay of Plenty Times by Peter White