hey i need your guys expertise, the hose that comes out the back of the intake manifold to provide coolant to the heater core, can i completely close those off or do i have to connect the two together using a plastic adapter. the reason i ask is because i took out my heater core, making a drag car out of it on a budget, and now i have these two different sized hoses. if i completely close them off will i cut off flow to the rest of the block? sorry for being long winded but i noticed everything goes smoother if i cover it all right away. oh yea and its a 2000 mustang gt with a auto trans, p.i. intake. thanks guys for any help or advice. greatly appreciated.

 

Here's a coolant flow diagram for the 4.6L:



You can see that the heater core return is the pipe/hose that passes through the valley between the cylinder banks--so it looks to me as though it can be capped off with no ill affect.