I am looking for the proper hose routing. For the spark thing on the passenger side firewall..
If by "spark thing" you mean the OSAC valve, it is plumbed in the vacuum line from the ported vacuum at the carburetor to the vacuum advance canister on the distributor.
The following image shows the vacuum hose routing for the Orifice Spark Advance Control (OSAC) valve:
Note that the drawing combines the three engine connection possibilities.
If the car is an original 340, it will not have an EGR Temperature Control Valve, part number 3656660, on the firewall, but if it was originally a 318, it could have one, which was originally connected to a carburetor vacuum port and the EGR valve via a single line. The other fitting on the valve had a small foam filter to effect the air bleed. The 340 did not have an EGR valve, but used EGR floor jets in the intake manifold.
The following image shows the EGR Temperature Control Valve, part number 3656660:
The following image shows the vacuum hose routing for the EGR Temperature Control Valve which would have been on a 318:
As well as the routing for the hoses from the fuel canister.\nTo the carburetor..
The charcoal canister is connected with three fittings, which are marked on the original factory canister as to their function. One smaller fitting connects to the vent line from the fuel tank vapor system. The other smaller fitting connects to the purge port on the carburetor. The largest fitting connects to the bowl vent on the carburetor. The following image shows a canister:
The left fitting is to the carburetor purge port, the middle fitting is to the fuel tank, and the right fitting is to the carburetor bowl vent.
The following diagram shows a general routing of the canister hoses connections:
The following image shows the 1973 Thermo-Quad carburetor and front port connections:
The port labelled "C" is the canister purge port. The unmarked bowl vent port is on the upper left, behind the solenoid.
The port labelled "E" is the ported vacuum connection to the OSAC valve.
Also, the vacuum temperature switch on the radiator has 2 hoses not sure where they go or how they are routed.Any help or pictures would be appreciated.Thanks
The radiator in a 1973 car originally equipped with a 340 does not have the EGR Temperature Control Valve, 3780140, which was relocated in from the firewall to the radiator after March 15, 1973. This was used on 318 Challengers. The valve connects the same as the firewall mounted valve with a single line and the other port has a small foam filter. If a late radiator with the valve provision was in a 340 car, it would have a plug instead of the valve. The following image shows the valve connection and is to be used in conjunction with the previous drawing of the 318 connections.
