Basically you will use everything from the 4g63, but since the 4g64 is taller block, the top screws dont match up well. I zip tied the top ones on my g4cs, had no worries.
I understand what Maui is saying. 7 lbs of boost is stock wastegate pressure without the boost solenoid hooked up, having the car completely stock with a E316g hanging off of it shouldnt hurt engine at stock boost levels. It should be common sense that 20 lbs of boost would require fuel mods...
Gauge probably reads in bar. Should check for boost leaks anyways as part of your maintenance, also could be your boost solenoid is not hooked up or missing and might need a manual boost controller.