[Fot] Drilling oil passages from main gallery to mains

[Greg & Alison Blake]

In a TR3/4 block, is there an advantage to drill out the oil passages
from the oil gallery to the mains?  If so, what size is optimal?
Neglecting (a lot of things) oil surges and viscosity break down etc.,
is the oil pressure in the system constant for a given RPM?  If pressure
in the system is constant, when I open up these supply holes more oil
would flow to the main and follow on to the rods due to a greater cross
sectional area for the same pressure and oil supply to the valve gear
would be unaffected because the pressure in the oil gallery is constant
and I have not changed the cross sectional area for the passage to the
valve gear.
 
Do I have this correct, or am I all oily?
 
Thanks,
 
Greg