The MTA’s controversial plan to demolish a block of Midtown to expand Penn Station has grown even larger and $4 billion more expensive — with a price tag that could now approach $17 billion, records show.

Newly revised schematics reviewed by The Post call for a terminal that would be far larger than the massive $11 billion one just dug under Manhattan’s Grand Central Terminal for the new Long Island Rail Road station — a project that ran so late and over budget it became a poster child for mismanagement.

The new Pennsylvania Station is being designed to fit extra trains to run under the Hudson River after the completion of the $16 billion Gateway Project. That project involves the construction of a new tunnel linking New York and New Jersey and refurbishing existing century-old Penn tracks that were badly damaged by Superstorm Sandy.

Originally, plans were to build an eight-track extension that would be largely confined to one block and carry an estimated price tag of $13 billion.

But the 200-plus-page revised Penn Station engineering document lays out three new plans for the expansion.

The first proposal would dig a cavern to build a 12-track station that would be split across two levels — and be 50% larger than the LIRR’s Grand Central Madison station — at an estimated cost of $16.7 billion.

The project would be mostly contained within the block between Seventh and Eighth avenues from 30th to 31st streets.

But the proposed 12-track station would no longer fit with the connections that are supposed to link it to the new Hudson River tunnel being built as part of the Gateway project, forcing officials to spend more than $280 million to redo the work.

The second proposal calls for a new nine-track station that would be split across two levels. It would allow the MTA to use the existing tunnels linking the station to the Gateway tunnel.

But the document warns that the nine-track proposal would likely sprawl well beyond Seventh Avenue to the east — potentially a third of the way to Sixth Avenue.

“[The station] would be located primarily … between Seventh and Eighth avenues and between West 30th and West 31st streets,” it states. “The station area would extend under these streets and would also occupy [the block between 30th and 31st streets and Eighth and Ninth avenues] to the west and more of [the block between 30th and 31st streets and Sixth and Seventh avenues] east of Seventh Avenue.”

That plan would cost an estimated $12.3 billion.

The third proposal would build a 10-track terminal to the north of Penn Station, beneath Herald Square — contained in the block bound by Sixth and Seventh Avenues between 33rd and 34th streets, which currently contains a Target and an H&M.

It would cost an estimated $15.6 billion.

Officials are believed to favor the first two proposals, to the immediate south of Penn Station, over the Herald Square plan.

The project’s outside consultants and designers justify the station’s ballooning size with an extraordinary assumption: This modern multibillion-dollar facility will be less efficient than the current century-old Penn Station complex.

It assumes that trains will spend an average of 22 minutes at each platform, which is more than double the time currently needed by the LIRR or New Jersey Transit to board and disembark.

Increasing the amount of time a train spends at a platform increases the number of platforms a station needs to handle more trains to fit its schedule.

None of the proposals examined in the 2023 engineering report attempt to wring more capacity out of the existing Penn Station complex by increasing the efficiency of its operation.

In 2020, the MTA outlined $3 billion in improvements that could boost the capacity of the existing Penn Station complex by as much as 45% by reworking the station’s middle section to install wider platforms and overhauling the station’s signals.

The move would have required the railroads to cooperate more closely on service and schedules, linking together the commuter rail networks — a proposal known as “through-running.”

Advocates have been pushing the MTA, NJT and Amtrak to consider plans that would make the existing complex more efficient because it would allow the railroads to scale back the Penn Expansion plans.

Instead, the Penn Expansion engineering analysis again examined two other “through-running” proposals it had already nixed — only to rule them out a second time.

The expansion is part of the two-prong Penn Station strategy that was outlined by former Gov. Andrew Cuomo. It was to be accompanied by a separate $7 billion program that would overhaul the interior of the existing Penn Station but would not add any transit capacity.

The 22-minute train-on-the-platform standard is yet another example of how design decisions are massively inflating the costs of MTA mega-projects. The Post previously revealed how the MTA is heavily dependent on outside firms and that excessive designs have added $2.3 billion to the price tags of coming projects.

The larger-than-needed subway stations currently slated for the East Harlem expansion of the Second Avenue Subway add $2 billion unnecessarily to the project’s $6.6 billion price tag, some experts have said.

They have added that the specs to electrify the LIRR’s Port Jefferson line call for installing nearly twice as many electrical substations as needed, at a cost of $320 million.

Preliminary designs for the coming Brooklyn-Queens rail link, the Interborough Express, call for stations far longer than the trains that will serve it, experts have said, though the MTA redacted the cost estimates, making it impossible to know what the additional cost is.