How can I sync two audio sources running at different speeds
Well, I sorta figured it out so I'll put it as an answer, although I hope someone comes up with a better suggestion.
I had to eventually cut one track into (approximately) 5 minute segments.  I placed my cursor at the end of each segment, held the shift key and did a click-and-drag with my mouse to perform a &quot;time shift&quot; until the tracks aligned.  Then, I moved the next clip up against the first and repeated the process.  I found if I did this with the entire track, it still went out of sync, so by chopping the track into (approximately) 5 minute intervals it kept it closer to sync.  That might be due to the speed of the source tape varying as the batteries got weaker.  I tried to cut the track near a large volume peak or valley to make it visually easier to align the tracks.
All in all, it was still much easier than trying to do this with something like Audacity or Sound Forge.