The question you ask is too involved for a proper answer. You need to go to a car parts store, and get a repair manual for your car. They cost about $16.00 Or, go to a Public Library.
The answer can be found at www.dippy.org. I just did this last week
The firing order for a 1985 Chrysler Fifth Avenue with a 318 c.i. engine is 18436572.
To replace the heater core in a 1985 Chrysler New Yorker, first, disconnect the negative battery cable and drain the coolant from the radiator. Remove the dashboard and any components obstructing access to the heater core, including the heater hoses, which should be disconnected from the engine. Replace the old heater core with the new one, reassemble the dashboard and components, and refill the cooling system with coolant. Finally, reconnect the battery and check for proper operation and leaks.
Try nada.com
18 Gallons
$300 - $400
15 to 18 mpg
35thousants.
The fuel filter on a 1985 Chrysler 5th avenue should be below the alternator on the passenger side of the car
NoNo
The dash has to be removed to gain access to the heater box. The heater box then comes out and is split open to replace the core.
depending on the accessories under the hood, it weighs approximately 3600 lbs.3300 - 3500 lbs (wikipedia.com: look up 1985 Chrysler 5th Avenue)