[kitcarbp]

Food for thought.
If your surge tank has the 5/8 or 3/4 "fill line" entering into the top of the low pressure side rad tank, its still not as good as it being connected to the bottom of the low pres. side tank or "Tee'd" into the suction (low pressure) hose leading to the water pump.

Why ? As you fill the system via the chrome surge tank where pressure cap is, in your configuration, the coolant will enter into the top of the low side tank and as it fills the rad core tubes will trap some air making it more timing consuming to burp the system after a few heat cycles. Not impossible, just more troublesome.

If the "fill line" is connected to the bottom of the low pres side tank or lower rad hose, during filling, the liquid will travel into engine block (via lower rad hose) and into rad and then force the air up and out from the bottom of rad core upward (via the small air bleed line at top of low side tank on my set-up). likewise as coolant travels into the engine block from the bottom, it forces the air up and out of the therm housing bleed valve.

Ahh the fun of custom cooling systems !