H'mm, you must've not gotten (or not liked) my e-mail answer to your similar question. What exactly is the nature of this sorrow of this sorrow you've been advised will befall you if you use the resistor you've bought?
A Standard RU-4 will work. So will an ACDelco C1101. So will various others. What brand and number did you buy?
What matters is the resistance, not the appearance. It doesn't matter if the new resistor looks like this
or like this
NAPA offer several different ballast resistors for early Chrysler applications. There's ICR11 (1.35Ω), ICR13 (1.82Ω) and ICR23 (1.20Ω). I'm thousands of miles away from my desk and FSMs at the moment, so I haven't got an FSM in front of me, but you can quickly check the resistance specification in the ignition specification section of your own FSM, then swap the one you have for the one you need if necessary.