can anyone tell me were to get a diagram how the heater hoses are run

 

There are 2 heater hoses, both are on the left side of your valve cover going into the passenger side firewall into the cabin. I'd recommend just doing a flush of the entire cooling system, then see if there's any improvement after.

 

yes there is but really need a diagram don't think heater control valve is right

 

What year do you have?

From what I have read, most people just get rid of the heater control valve since they're prone to failure. I'm pretty sure I've seen Salad post about this multiple times. Try searching for other threads and see what they say.

 

1990 inline 6