On a 4x4 Cosworth you have got a bleed point on the thermostat housing too

Small(8mm IIRC)bolt on the top of the thermostat housing,undo it once you've filled the coolant up untill the coolant comes out,then replace bolt

Never had to remove the hoses at the bulkhead on either of my cosworths,just leave them ticking over with the header tank cap off upto normal running temp