"From a maintenance standpoint, that bleed split is unexceptable. Off the head, I believe the limit for splits is 8 psi."
Is this any different from the NG, B73567AMT? I'm currently looking at a 737NG simplified bleed pressure diagram (N1 Vs Bleed Pressure, for sea level to 5000') in the Maintenance Manual D&O and, at N1's above 65~70, the pressure can be 42psi +/-8 psi (as modulated by the PRSOVs). This gives a possible range of 34 to 50psi. Even so, Arba's 12psi is well outside this range.
Regards.
Q.