well really depends if you are talking c model d/e model or Notar
You are looking at around 1800 ft a min for a c model and around 2200 for a D. Does depend on how heavy and how the auto revs are set.
I now teach in a D model at 125 kts at around 1000ft shut the throttle hold the lever up at the cruise and haul back on the cylic. The aircraft will climb at about 500 ft a minute for around 5 o 10 seconds. As she reaches 80 kts ( best range speed )and the bottom of the green arc lower the lever, this drops the nose and allows speed to build up again and will allow you to haul back the cylic which will increase rrpm back to around 480 and a rate of descent will build up to around 2000ft a minute as you get back to 60 kts. Range with this technique is a good 1 km plus.
Hope that helps