i'm using 40 lb injectors on my gen1, with an adjustable rising rate fmu. base pressure is about 30 psi and the pressure rises about 6 to1, which allows me to have my pc3/5 fuel map zero'd out as the boost climbs. 6 to 1 at 10 lbs boost is 90 psi fuel pressure at a 30 lb base pressure setting. an adjustable rising rate fmu is mandatory as far as i'm concerned. this requires a high pressure fuel pump; i'm assuming you upgraded your pump, but be carefull as not all aftermarket pumps are high flow at the higher pressures. you need to look at the actual flow map for the pump your using. most pumps will have high pressure but will not flow high volume past about 70psi; it literally falls flat. this is not common knowledge. Walbro is what i use, and you can google flow charts for their pumps to make sure your getting the one that actually flows high volume at higher pressures. i use an external pump mounted under the tank bolted to the frame behind the engine, and the adjustable fmu is located in front of the engine under the front tank mounts. this means there is high pressure fuel and return lines running everywhere, so connections and fuel line placement is critical for safety. have fun. i built my own also.