>"why not use AFCAD to say they're shorter?"I keep meaning to try this, but the weekends are only so long and there are so many great aircraft out right now... The only reason I didn't try that first is because AFCAD then shows the gray runway image as being shorter than the runway nodes. I don't think this will affect takeoff because ground AI aircraft follow nodes not runways (I think!). Longer was used only because it minimized the uncontrolled variables in the experiment. I'll try shorter and report back.

I finally tried you idea of making both runway lengths equal to the shorter of the two. This causes departing aircraft not to use the entire runway length.So I went back to making both runways equal to the longer length and then (using AFCAD) shifted the center position of Rwy 3/21 to the south. I also closed rwy 3 for both departures and arrivals (which is 99% realistic for KPDX). Arrivals no longer land short of rwy 21, however heavies now have a tendency to overrun on arrival. This will be solved by creating a third overlay that restricts heavy aircraft to 28L/10R only. This is probably the best I can hope for with this version of FS.