I took the coolant hose at the rear iron and found a heater hose at the parts store to route it in the back of the water pump. I wanted to double check that I'm not screwing up any of the coolant flow by doing that. The previous owner capped it off with one of those vacuum caps, and I don't trust it

 

You are fine. A lot of people "loop" that coolant line.

 

Cool, thanks. I didn't think it makes a huge diference