Cylinder #1 is on the far passenger side. The posts on the coil are numbered.
clockwise on the distributor 1-8-4-3-6-5-7-2
check haynes manual "firing sequence" or "firing order"
Check to make sure the wires are all tight and you have them in the correct firing sequence. Also make sure you put the correct plugs in.
the ignition coil
If it is backfiring the timing is set incorrectly or the spark plug wires are not connected in the correct order.
With a Spark plug gap tool :)
Fallow the plug wires!
Need the firing order for spark plug wires to distributor on a 1978 Dodge 440
List your engine size next time. http://autorepair.about.com/library/firing_orders/bl-dodge-firing-98.htm
Spark plugs and wires
firing order is: 1,8,4,3,6,5,7,2