CT is mostly determined by the head / tube design with the pack also having some effect. If you are familiar with your grafit you know you can control CT in 50K steps by the use of the FCC meter or just by dialing in a shorter (+blue) or longer (-blue) flash duration.
While it is not a big deal to rewire off brand heads I would still recommend the help of a dedicated service specialized for this task and knowing what they do. All the brands you mentioned above have some special heads for short flash duration (called speed, quick, X or whatever) that will fry the cut off circuit of your grafit pack, which will be a very costly repair. You can instantly recognize these tubes either being in a closed ring design, having three electrodes (plus the trigger) or two tubes in parallel (Balcar). Don´t underestimate this risk! If you can measure the flash duration (FCC) it has to be in the range that is displayed when using port 3 of the grafit pack. This output is not controlled by the electronic IGBT output stage, is safe with all tubes and will show how the unit works on your pack. If the flash duration is way shorter than displayed NEVER use it on outlet 1 or 2. Nominal capacitor voltage of the grafit is 700Volts, trigger coil voltage is 300Volts against PE (with the trigger capacitor being in the pack) that is pretty common and suits most of all brands heads. Careful with Elinchrome heads, they need to be changed in the head wiring as well as their trigger coil is connected to the negativ electrode, Hensel has the capacitor in the head (very old design in the plug), this should be removed for safe plugging, not sure about Balcar, check! Please consider if it is worth all the effort if you need to buy the off brand heads. We have some off brand light bars and other stuff running from grafits and also some Briese heads (now broncolor has good Paras, so this is not essential any more). All running fine since many years. HTH, Cheers, Ulf