I have a 56 GMC 100 with the original Pontiac 316. The truck came with the heater supply hose capped-off and now that I'm installing AC would like to complete the routing so it will have heat. It appears that the water pump does not have a dedicated inlet for the heater hose. The radiator does not have a dedicated heater inlet either. The fuel pump is capped-off and an electronic one was installed by the former owner. Any suggestions how to properly complete this project? Someone suggested tapping the lower portion of the radiator and installing a nipple.