I did this route, below, quite a while ago, from West Alexander, Pa., to the free bridge in Easton, I'd try to do most of it on a weekend though. Theres 15000 feet of climbing so be prepared for it. Gorgeous scenery, a few busy areas; Breezewood, Chambersburg, Harrisburg, Easton, depending on your timing. Finding Old route 22 as you exit Harrisburg to the east was a ***** at night. Also on Old 22, at one point, there was a weird jog that we had to do and go over I 78 on the north side, then come back over, as I believe Old 22 got swallowed by I 78 at some point. This was about 80 miles west of Allentown.
Mapmyride, search, Don Yatko Memorial Race Across Pennsylvania