I understand that it's older, but that doesn't necessarily mean less powerful. I've been on many a Delta 727's and they have plenty of power.  I was trying to take off at KSAN and with only a half full plane, I should've had no problems getting off the ground. I've also tried this at EDDN(took entire runway),KDFW(took most of runway), and LOWI(overshoot) It seems to take a lot of runway(more than it should) to get up to speed. If no one else is having issues I will try a complete uninstall and reinstall to see if it's any better. As it is if I have less than an 11,000ft runway she'll overshoot the end before rotating.

-Todd