This page illustrated the routing of the heater hoses from the engine to the heater core and back.
From This C10
General placement of heater control valve and vacuum canisterPlacement of heater control valve on inner fender. Also note vacuum canister on A/C box With the first Edelbrock Performer intake manifold, heater hoses run under the A/C compressor and cinched by a bracketNote screw holes and wear mark for heater control valve on inner fenderAfter the new Edelbrock Performer intake manifold, runs over the A/C compressor
