did not install auxillary tanks on the 734s, because AS
carries so much cargo to/from Alaska and that would take away from payload. I know they did (perhaps still do) have auxillary tanks on a few MD
-80s, but they are no longer needed since AS
uses 737NG for all it's long-haul routes now.
According to the airliners.net aircraft info page, the max range of a 737-400 with full load of 146 pax is 1960 nm which is 2260 mi. Obviously there are a lot of factors (pax/cargo load, temp and wind at departure city, dept runway length, en route weather/winds) that will affect the range. But, I still wonder if this flight would be even possible with max payload.