Dirk, The Surge tank large diameter (5/8) line on the WC is referred to as the FILL line and gives you a convienient place to be able to fill the coolant system when radiator is mounted below the height of the engine. The surge tank needs to be the highest part of the cooling system to collect and purge trapped air into the coolant recovery reservoir. Trouble is the surge tank is a little lower than therm. housing. Our WCC and most systems are an "outlet temp controlled system" (thermostat is on the engine outlet upper hose) and the fill line needs to feed into the low pressure side of the cooling system. For the 460 in the WC, this means you have three choices for plumbing.
1) Feed fill line into top of rad outlet tank (low pressure side of rad)
2) "T" into the lower rad hose. (what I did because it was easy)
3) "T" into the by-pass pipe between water pump and intake manifold. (WIZARD did this on his WCC)
Read the section under RADIATOR CAP LOCATION at this link for surge tank info.when using a cross-flow rad mounted lower than the engine.
http://www.stewartcomponents.com/tec...ech_Tips_2.htm
With that said, burping this system is a PITA. Therm. housing as a threaded port to aid burping at fill-up and thermostat should also have by-pass holes (I drilled my own) to allow any remaining trapped air to exit the engine and enter the radiator while running to facilitate air from exiting the engine. You can also loosen water temp sensor in the intake during re-fill to burp engine. The rad low pressure side (outlet tank) has the air bleed line connected to the very top of outlet tank on the rad back into the top of the surge tank (also called de-gas line). Flow restrictors are not needed and will inhibit cooling in a street application, thermostat only! see this link
http://www.stewartcomponents.com/tec...ech_Tips_3.htm