What spark plugs, wires and cap for a stock '71 318?
Mopar Performance P4529791 if you want to stay with a tan cap. Make sure it has brass inside, and not the aluminum junk.
If you are not worried about a tan cap, Standard Blue Streak makes a very good cap and rotor.The cap comes in blue or black. Again, make sure the cap is brass, and not aluminum.
Blue Streak cap....CH-409
Blue Streak rotor...CH-303
The rotor can be used with either cap.
Summit, Jegs, EBay is where they can be had.