The company gave reporters and photographers a look at the line Tuesday as production increases from 35 planes a month.
"We broke a record last year by producing the 737's at 35 a month. 38 is a new record for us," said Beverly Wyse, Vice President and General Manager of the 737 program. "And next year, we'll go up to 42 and set another record."
Boeing has a big backlog for the best-selling jetliner that was introduced in 1979. Over the decades, more than 10,000 737's have been built, including more than 4,000 of the current Next Generation model. That version is the most widely flown jetliner in the world.
The company says producing more aircraft every month also means more jobs, and in the past several months, anywhere from 500 to 700 new jobs have been added on the assembly lines.
By 2017 Boeing expects to start delivering the newest version, the 737 Max.