hi,i'm trying to find out what size injectors my 70mm au maf is calibrated to,19lbs or 24lbs,i want to use with my 30lb xr6 turbo injectors on my eb xr8 stroker,i understand that these injectors need a higher fuel pressure but if i use standard pressure they should flow around 24-25lbs so i could get by with that maf.

OEM MAF's are not calibrated for any injector size.

Calibration is a "hack" used on aftermarket MAF's to re-scale the airflow signal.

Those XR6 Turbo injectors are just the same as std non-XR injectors. They run the fuel rail at a higher pressure as you mentioned....so for all intents and purposes, they are 24lb injectors.

If your EB has twEECer support, then have a tune done to suit the 24lb injectors and 70mm AU MAF. Chiptorque, and CAPA Eliminator chip can also do this.

Ok,i do have a unichip to be fitted later this should solve my probs,but can i drive this with those injectors for the time being or will it be too lean?
my new motor has just been finished and goes into the car on thur- friday,my engine builder wants to put the 19lb back in for now until we update the fuel pump, reg. and computer mods.don't want cause any damage,this rebuild has cost me a packet.

I cant see the Unichip working very well at all with a different MAF and larger injectors.

It is not an "edit" like the twEECer, Chiptorque, and CAPA Eliminator are. Its a signal bender/interceptor/piggyback...and it will be over its head trying to manipulate the signals to make the different MAF and injectors work at idle, cruise, transient throttle, and WOT.

Sell the Unichip, and go for one of the other options....CAPA Eliminator chip or twEECer would be my pick (in that order).