what is the factory setting for a 1987 z28 with a 305 tpi and an automatic? how much can i safely crank it up? and how do i do so

 

I have a stock 85 IROC TPI. My fuel pressure with stock regulator is 44lb. at idle with vacuum line removed. I think the range for these is someplace between 37-45 from the factory depending on the year...the higher end being prefered i would imagine.