Nitrous fuel pressue info needed

I have read ,resurched,talked to tech idiots,and my local nitrous expert that tells me differnt,things every time I talk to him.PLEASE bear with me.This is a slant six car that has 6 national records last year,,,best run all motor is 11.43 at 115. at 2345lbs.I now want the nitrous records.I have installed direct port foggers in my runners with a black pump y ed into carb and solonoid.Am only going to spray it with a 60 shot,16 and 18 jets.This is a 238 cubic inch motor around 12.3 compression..My local guy said one day 5.1/2,open then the next day said 6.5???? dead headed.Then called NX and they said 10 lbs open.ANY advise wanted.I right now have it set at 6 lbs open cause thats the only number i havent heard,,,just the way I am.PLEASE PLEASE,any input or opinion wanted.Guzzi Mark