Block off plate for water pump rear water outlet?

[1984ranger28]

Hi, the bottom left water outlet has cracked on my 2.8l. It routes a hose from it to the top water inlet with the temp sending unit and sensor. My question is that if I made a block off plate for the rear water pump outlet and plugged the nipple fitting would this affect cooling? Thanks, Lucas.

 

[AndyB.]

That’s the bypass, it circulates water through the engine when the thermostat is closed—don’t block it off, find a replacement.