Great input here. At a risk of being monstered, I will add one more comment on the suggested modified arrangement which I have also mainly adopted for my car . I am running the original factory radiator.
Because of the tube diameter , distances and various pressure drops within the system I found that a 15pSI cap on the red swirl tank complemented by a 13 PSI cap on the blue makeup tank was a balanced combination that saw little in the way of any coolant vent discharge and resulted in a really well balanced self venting system. The pressure drop from the radiator vent back to the makeup tank circuit on startup is the full 15PSI which ensures the scavenging of any vapour pocket developed in the radiator. Subsequently when its lined out at full operating temperature the system settles at full pressure in balance internally with little or no venting.
No overheating, strange gurgling noises, puddles of shame on the floor, no dieseling on shutdown , no coolant loss - just a well behaved cooling system.
Great solution.
