Taranaki Mounga plans a two stage "remove and defend" assault using the toxin beginning in March.
A second 1080 drop, also targeting possums, will cover 31,000ha over the remainder of the national park, including the Pouakai Ranges, later in 2019.
The group will also work with community groups and iwi to target stoats using traps in Kaitake and Pouakai Ranges, and Kaupokanui, South Taranaki in late 2019.
The aim is to get predator numbers to less than five per cent, and restore the ecosystem and enable native birds, such as kiwi, and fauna to re-establish in the national park.
Taranaki Mounga project manager Sean Zieltjes said while the first stage of the operation in the Kaitake Ranges would target possums, rats, stoats and ferrets would be part of the "beneficial by-kill" of the operation.
The pest programme runs alongside the $11.7m Towards Predator-Free Taranaki project co-ordinated by the Taranaki Regional Council and funded by Predator Free NZ, and involves a number of volunteer groups in clearing urban and rural areas of predators by 2050.
The regional council is also co-ordinating a pest operation amongst rural residents bordering New Plymouth.
"The remove and defend operation objective is to kill possums and prevent them from re-establishing, but every pest in the park will also be targeted," Zieltjes said.
"The operation is innovative and ambitious but is essential because we have huge numbers of pests in the park."
A pre-feed operation will occur in March before Ospri contractors start releasing 1080 within six weeks of the pre feed.
It is the fourth aerial 1080 drop to be co-ordianted in Egmont National Park since 1992.
The entire national park will have been covered by the aerial 1080 operation by the end of 2019, Zieltjes said.
Zieltjes said the group expected anti-1080 protests when the operation was underway.
"The operation here is the earliest in New Zealand to get the best weather window.
"We've had meetings with stakeholders and iwi to let them know what is happening, and we are being as open as we can with our intentions."
In 2016 six anti-1080 protestors blocked access to motorists at the North Egmont entrance of the park.
Taranaki Mounga also used around 2160 A24 gas powered self setting traps, and 3000 DOC200 traps for pest control in the Kaitake Ranges and over a 1000ha area in the national park.
"The A24 and DOC200 are both good tools but we are unsure if we can deploy enough of them over the area to be efficient," he said.
"1080 is best for larger predators like possums, while the DOC200 trap is ideal for stoats, and the powerful DOC250 is more suitable for ferrets.
"Our aim this year is to find the best tools available, and we have to have something that works.
"We have incredibly high rat numbers in the park as shown by our tunnel tracking, and the rats decimate the native birds."
Added to the task for the group in 2019 is an expected high "mast" event of native trees, including rimu, from late summer onwards and peaking in autumn, he said.
"We will get an unusually high amount of fruiting from the native trees which meant more food for pests."
The mast is described as a "fruit salad" feast for pests, he said.
"As a result we expect to get rats, rats and more rats."
Zieltjes said the widespread use of 1080 in the national park was essential to keep pest number manageable.
"The DOC200 and A24 traps would not efficiently target all the pests in the context of our remove and defend targets.
"Once the possums are removed, the traps will be used to prevent them from re-establishing."