MGB Do I need a heater valve?

[YakkoWarner]

As I get (creepingly slowly) closer to the point of possibly seeing if my 20+ year dormant engine will make some noise, I am wondering about the heater valve and that weird in-line T off the lower radiator hose. I have no idea if the heater core in my 1973 body is even any good or not (and looking at the diagrams it seems like the most likely way to replace it involves a cutting torch and a lot of welding afterwards). At least for the short term I'd like to leave it out of the system completely, and I am wondering if it is necessary to run a hose loop from the heater valve to that lower hose T fitting, or can I just blank off the valve port on the head and not have the lower hose T at all. If the heater hose loop is crucial to proper water flow thru the head, then I certainly don't want to leave it off and I'll just bypass the core. I had replaced the valve under the assumption that at some point I'd want to try the heater core, but now I'm starting to get nervous of that.

 

[Joe Reed]

If the heater valve is closed there is no coolant flow through it. Blanking it off does exactly the same thing.