Capital costs are now expected to be US$2.82 billion, up from $2.65 billion in the 2016 prefeasibility study.
The costs include a 140MW power facility for the 17 million tonne per annum Watut plant, deep-sea tailings placement, two pipelines, new facilities at the Port of Lae, a water treatment facility, an access road, 1400-person accommodation camp and surface workshop.
But sustaining capital has fallen from $3.72 billion to $2.55 billion, lowering overall project capital to $5.38 billion.
The development proposes three block caves, including an initial 16Mtpa cave, which is larger and deeper than previously envisaged.
Average annual production over the 28-year mine life is set to be 161,000 tonnes of copper and 266,000oz of gold, up from 130,000t of copper and 202,000oz of gold.
C1 cash costs are expected to be just 26c per pound of payable copper, or negative $2128 per ounce on a gold all-in sustaining cost basis.
Free cashflow generation over the life of the mine is expected to be $13.1 billion.
The study returned a net present value of $2.6 billion, up from $1.9 billion, an internal rate of return of 18.2%, up from 17.5%, and a payback period of 9.5 years.
"The improved business case set out in the updated feasibility study clearly demonstrates the world-class nature of this multi-decade project," Newcrest managing director and CEO Sandeep Biswas said.
"At Newcrest we are excited to have this tier 1 asset in our portfolio with an IRR of 18%, first quartile production costs and decades of operating life."
Newcrest is aiming to have five tier 1 assets in its portfolio by 2020 - with Wafi-Golpu, Cadia, Lihir and newly acquired interest in Fruta del Norte the four the company is currently exposed to.
Newcrest and Harmony are targeting the submission of an amended supporting document for the special mining lease (SML) application by Wednesday.
The original SML application was submitted in August 2016 and the development timeline depends on its approval.
Fellow PNG developer PanAust submitted an SML application for the Frieda River project in June 2016, which is yet to be approved.
Newcrest said first production from Wafi-Golpu could be achieved around 4.75 years from the grant of the SML.
An environmental impact statement is due to be submitted by the end of June.
"We have a clear pathway forward for the project and together with our joint venture partner, we are committed to working with the government and people of PNG to progress this world-class asset," Biswas said.
RBC Capital Markets analyst Paul Hissey said the project was an important part of Newcrest's growth strategy, but the long lead time to production meant that it was unlikely to have much of a market impact in the short-term.
"Nonetheless, there is merit in a longer-term strategy, which sees the company building a portfolio of long life, low cost, high quality projects," he said.
"We believe investors continue to focus on Newcrest as a long-term investment position, and are likely to be more disposed to the opportunity at Golpu than any potential drag from the recent tailings incident at Cadia."
Newcrest had net debt of $1.4 billion at December 31, including cash of $556 million.
However, it is a huge project for Harmony to fund alone - its market capitalisation in Johannesburg is just under US$1 billion compared to Newcrest's market value of $11.7 billion.
Harmony CEO Peter Steenkamp last month acknowledged that the market was not ascribing any value for Wafi-Golpu.
"And we certainly would like to be in a position where we can create some value for our shareholders out of that particular project. And it can be many things, I mean we would know in a year or year and a half from now, what will it all look like at the time," he said.
"I mean we don't know, but we can build it, we can get partners to help to fund that.
"We are very excited again about the project. I think it -- from a money perspective, you can probably not find a better ore body than that, and good grades both in copper and in gold. So, it's certainly a very, very good project."
The PNG government has a right to acquire 30% of the project at a pro-rata share of exploration expenditure before the start of mining, which would reduce each company's share from 50% to 35%.