Ideally, when migrating from one fgt model to another, both devices should be on the same firmware. Then it would be a matter of copying the header line from the target model' s config file and pasting it into the source fgt' s config file.
If the ports do not match up on either fgts, you will need to substitute or duplicate (i.e. virtually create) the old ports on the replacement fgt. (There are several threads on these forums about this.)
Fortinet has provides a firmware
upgrade path to help you with getting your fgt device to a firmware you want. Unfortunately, 3.0 MR7 Patch 10 is the last firmware update for the 60. And the earliest firmware for the 60C seems to be approx. 4.0 MR2 patch 2 (or there abouts). (Too lazy to look up the actual version numbers, but I think rwpatterson has a list.)
You may be better off putting both fgt devices side-by-side (browser-wise) and " manually" replicating the config settings from the 60 to the 60C. (Personally, I would load up both the 60 config and a clean 60C config into Winmerge (or other text comparent tool) and selectively " migrate" settings over.
NSE4/FMG-VM64/FortiAnalyzer-VM/6.0 (FWF30E/FW92D/FGT200D/FGT101E/FGT81E)/ FAP220B/221C