Boeing's marketing chief Randy Tinseth expects the 737 Max family to rack up "hundreds" more orders in the coming months as the airframer works to firm the configuration of the new narrowbody.
The airframer launched the new family in August with deposits from five undisclosed customers - known to include American Airlines - for 496 commitments.
These deposits were taken despite the fact that the aircraft is relatively undefined "because our customers understand the aircraft today, they understand the work statement we're talking about and they know where we're going," said Tinseth, who is Boeing Commercial Airplanes vice-president marketing.
Tinseth said details of the 737 Max's performance specification are still being finalised with range, weights and engine fan diameter still fluid. He expected the firm configuration would be achieved in "the next weeks and months to come".
However, Tinseth is confident 737 Max sales will quickly accumulate.
"We have those 500 commitments from five airlines, and as we go forward in the next months I expect that to increase by hundreds," he said.
The order boast comes after John Leahy, chief salesman at rival Airbus, poured scorn on Boeing commitment claims.
"I hear from my competitor that he's got 496 potential commitments. I can't for the life of me figure out where they are - other than American Airlines," he said.
A decision key to the 737 Max firm configuration effort is the engine's fan diameter, with 66in (1.68m) and 68in being evaluated, compared with 61in on the current models. "I expect we'll decide this sooner rather than later," said Tinseth.
He added that the fan size could also have a knock-on effect on the engineering of the landing gear.
"We're looking at a potential modification to the nose gear to make it a bit longer - a 66in fan diameter reduces that risk and there may be a chance we don't have to [touch the gear] with whichever fan size we go for," he added.