LT-10s - S5 Rx-7

Can I use another trailing coil pack in place of my leading coil pack?

I have an extra one sitting on the shelf here.
Would there be any benefit?

I've read it's better to have one coil per plug.
And I'm having problems with really weak spark on the stock leading coil
-could be the coil pack isn't grounded to the body well enough.
(I need to check it out when I get home from work)


Is this possible without the X4 ignitioin setup?
How should I connect the wires?


Also, is it possible to upgrade to the X4 ignition setup without sending the ECU back for a reprogram?