For a job like this, you may be better off using an editing application. Most will let you defing the duration of stills, then you simply add them to the timeline and you're done.
But you'll end up with an hour-long video file. It seems like a lot of file space for 60 stills. Do you have another way to play them back in order?
Agree with Dave. It would be better to simply export them manually. 60 images really isn't that much. I've done exports this way with hundreds of images at times to patch up botched 3D renderings. It's merely a matter of patience and finding something to distract yourself while you hit Ctrl+Alt+Save repeatedly...