Industry sources said the US planemaker, struggling to maintain its duopoly with Europe's Airbus, would strike early at the Farnborough Airshow, which opens on Monday, after months of talks to sell its largest single-aisle jet to Delta.
Reuters first reported in March Delta was discussing an order for 100 MAX 10 planes, and reported last week the airline was also in talks to order around 12 more Airbus A220s in a deal likely be announced on Tuesday.
Germany's Lufthansa is likely to firm up a deal for around 10 large Boeing freighters, including seven of the recently launched cargo version of the 777X, sources said.
None of the parties commented ahead of the show, which is going ahead despite an emergency UK weather warning and restricted rail access caused by record forecast temperatures.
As Britain melts, aerospace firms will do their best to show civil demand is intact after the worst downturn in their history. Rising defence spending will also be in focus as the industry gathers under the shadow of war in Ukraine.
Boeing unveiled broadly stable civil aeroplane forecasts on Sunday.
Even so, many of the deals will be provisional ones or formal signings of business already in the works, and virtually all will be packaged as contributions to lower emissions in support of a common goal of net zero by 2050, delegates said.
EasyJet aims to secure shareholder approval for a recent deal for 56 Airbus A320neos, placing it on Farnborough's radar.
Poland's LOT is studying proposals from existing suppliers Boeing and Embraer as well Airbus and engine firms, but will not make a decision at the show, a person close to the talks said, denying a report the airline had already picked Airbus.
But most attention will be on the MAX 10 and 777X which Boeing plans to fly in a scaled-down Farnborough display.
Both aeroplanes are the source of major headaches as Boeing wrestles with regulatory problems in the wake of a two-year safety crisis triggered by crashes of a smaller MAX.
Boeing has a December deadline to win approval for the 737 MAX 10 - the largest member of its single-aisle family - or meet new cockpit alerting requirements, unless Congress waives it.
Chief Executive Dave Calhoun has said Boeing could be forced to cancel the 737 MAX 10 - a move that could have repercussions across the industry including for rival Airbus, reluctant to be dragged into a race to develop new jets too soon.
However, the head of Boeing's commercial division, Stan Deal, told reporters on Sunday that cancelling the MAX 10, which analysts say is needed to compete with strong sales of the Airbus A321neo, is "not a high probability path".
Boeing is also close to delivering its first 787 in a year after a spate of regulatory and production problems, Deal said.
Aerospace leaders will also be under pressure this week to address concerns over supply chains and a spike in inflation that raises questions over both input costs and consumer demand.
Current market leader Airbus is sticking with plans to raise single-aisle A320neo output to 75 jets a month in 2025 from 50 now, but some suppliers fear supply chains may not keep up.