I blocked the head outlet off too (about 30 years ago!) .Routed the return heater hose into the top of the water pump and used one of the bottom radiator hoses that doesn't have the heater return pipe sticking out the top of it (which can be a weak point where it joins the bottom hose anyway). Drilled some 1/8 holes around the perimeter of the thermostat.

_________________
Slide
1965 Mini Van (1360)
1970 Mk2 Cooper S (1310)
1978 Rover SD1 V8 (4.6)
1996 Land Rover Discovery V8 (4.0)