help me..where does heater control valve go??

[Evan's f250]

I have a 1978 F250 with a 351m and the in cab heater box..My question is if the heater control valve goes on right or left side (standing in front of the truck) and if it connects to the hose coming off the water pump or the one right above the water pump (between water pump and intake) i have the inline type control valve to put on...the hoses by some1 were bipassed bc of bad heater core

 

[DNFXDLI]

On my 79 with a 351 and facing the cab, the control is on the right hand hose and the right hand hose then goes to the block at the front.

 

[Mil1ion]

 

[Evan's f250]

thanks,nice diagram