I have found through reading lots of POH's and also through aircraft I've flown, that there is a close correlation between best climb and best glide speed for any given configuration.
This means that in my A/C, if I know no different, I'll always pick 55kts with flap and 62kts without flap to achieve best glide should the donkey quit.
I suspect that the correlation is a common one. Perhaps Pilot DAR or Genghis can verify/bust this?