Bottle pressure is more temperature dependent than % full. I would have said decent pressure was around 900 psi. Bottle heaters may well kick that up. My ZEX dry kit bumps the fuel pressure to about 60 psi (<55 shot mode) which is as high a pressure as I am comfortable with. I have no real basis for that comfort conclusion though. Also, if you have a wet kit your fuel pressure will be quite a different situation. Do you have any gauges such as A/F or EGT? I would recommend that you get something to warn of lean running. Otherwise, start known rich, listen carefully for detonation and check your plug condition frequently until things dial in.