You want to run the hose from the upper outlet on the water pump manifold straight to the heater control valve. That valve absolutely MUST be in betwen the high pressure outlet and the heater core!!! Unless you like making your heater core swell and leak. To save the heater core from an early death, you need to have the heater core hooked to the low presure fitting (suction) at the lower water pump fitting. Have the heater valve in between the core and the high pressure outlet at the water manifold (or cyl head outlet or thermostat outlet) . If you've ever had a car that smelled of antifreeze when you kick it into passing gear, then chances are that the heater core was not protected from the very high pressure surge by the heater valve in the proper place in the circuit. Make the sure heater valve protects the heater core from the high pressure surge that appens when you rev the engine!!! David LeVesque ++++++++++++++ I recently read somewhere (Avanti Mag??) an article or mention about the wrong pressure (lower press ) rad cap being used. ANY CAR MAKE-- if you run into that on a car you just picked up check the hose routing!! If you have trouble with heater core leaks, CHECK THE HOSE ROUTING. My Dad's low mileage Concord kept the dealer busy replacing heater cores. The dealer hated to see us coming. I fixed the problem the dealer couldn't. Improper hose routing. If someones heater keeps leaking the first thing most people want to do is lower the cap pressure. Look at air contitioning-- pump-- orifice-- high-side/low-side in many ways like a cooling system! The lower radiator hose is the suction hose. any heater hose fitting right at the lower hose or one that meets at the center of the pump is the suction side. Any hose fitting that comes out at or near the thermostat outlet, the upper part of the water manifold, the intake manifold (brand X), a cylinder head fitting or upper block fitting is the HIGH PRESSURE side. So What ??? My cap says 12 lbs so the pressure must be 12 lbs! Nope. The cap-leak pressure is 12 lbs, not high side pressure. No such thing as high side pressure? Why is there a wire coil in the LOWER hose??? To prevent collapse by suction in a12 lb pressure? Right. Wazzat mean? The water valve, or temperature valve, or temp control, is exacty like a throttling valve or orifice valve or expansion valve in A/C. Anything between it's restriction and the pump outlet is HIGH pressure. Anything between the restriction (valve) and the pump INLET is the low side. THE ONLY RULE TO REMEMBER-- NEVER PUT THE HEATER IN THE HIGH PRESSURE SIDE. Simple once you know why. Always always always run the upper (high press side or "outlet" side) heater hose straight to the control valve FIRST, then to the heater, then run the heater's return line to the suction or lower fitting. If you've ever hit passing gear and wondered why you smelled antifreeze, check your hose routing. Simple to remember-- outlet high pressure , use restrictor (straight to valve) heater goes to low pressure suction line. I hope I've helped someone. David Levesque ==================================================== Feb 2008 Jack and Kerry; the 45 degree tube on the heater control valve of '62-'66 Lark Type cars is the one that gets the short (3 1/2"-4" on each leg)"L" hose that goes to the forward tube on the heater core. That leaves the rear heater core tube getting the hose to the Water manifold LOWER fitting (return). And then the straight tube on the heater control valve would have to go directly to the (Hot) output, the UPPER water manifold fitting. StudeRich (SDC FORUM) - http://www.studebakerdriversclub.com/sdc_forum/topic.asp?TOPIC_ID=13940